United Ireland

Legal basis

Article 3.1 of the Constitution of Ireland "recognises that a united Ireland shall be brought about only by peaceful means with the consent of a majority of the people, democratically expressed, in both jurisdictions in the island". This provision was introduced in 1999 after implementation of the Good Friday Agreement, as part of replacing the old Articles 2 and 3, which had laid a direct claim to the whole island as the national territory.

The Northern Ireland Act 1998, a statute of the Parliament of the United Kingdom, provides that Northern Ireland will remain within the United Kingdom unless a majority of the people of Northern Ireland vote to form part of a united Ireland. It specifies that the Secretary of State for Northern Ireland "shall exercise the power [to hold a referendum] if at any time it appears likely to him that a majority of those voting would express a wish that Northern Ireland should cease to be part of the United Kingdom and form part of a united Ireland". Such referendum may not take place within seven years of each other.

Nationalist Context

The Government of Ireland Act 1914 (previously known as the Third Home Rule Bill) provided for a unitary devolved Irish Parliament, a culmination of several decades of work from the Irish Parliamentary Party. It was signed into law in September 1914 in the midst of the Home Rule Crisis and at the outbreak of the First World War. On the same day, the Suspensory Act 1914 suspended its actual operation.

In 1916, a group of revolutionaries led by the Irish Republican Brotherhood launched the Easter Rising, during which they issued a Proclamation of the Irish Republic. The rebellion was not successful and sixteen of the leaders were executed. The small separatist party Sinn Féin became associated with the Rising in its aftermath as several of those involved it were party members.

The Irish Convention held between 1917 and 1918 sought to reach agreement on manner in which home rule would be implemented after the war. All Irish parties were invited, but Sinn Féin boycotted the proceedings. At the 1918 election Sinn Féin won 73 of the 105 seats; however, there was a strong regional divide, with the Ulster Unionist Party wining 23 of the 38 seats in Ulster.

Sinn Féin had run on a manifesto of abstaining from the United Kingdom House of Commons, and from 1919 met in Dublin as Dáil Éireann, this body later known as the First Dáil. At its first meeting, the Dáil adopted the Declaration of Independence, a claim which it made in respect of the entire island. Supporters of this Declaration fought in the Irish War of Independence.

During this period, the Government of Ireland Act 1920 repealed the previous 1914 Act, and provided for two separate devolved parliaments in Ireland: Northern Ireland for the six counties of Antrim, Armagh, Derry, Down, Fermanagh and Tyrone, and Southern Ireland for the remaining 26. Section 3 of this Act provided that the parliaments may be united only by identical acts of parliament of the House of Commons of each parliament. While the Parliament of Northern Ireland sat from 1921 to 1972, the Parliament of Southern Ireland was suspended after its first meeting was boycotted by the Sinn Féin members, who comprised 124 of its 128 MPs.

A truce in the War of Independence was called in July 1921, followed by negotiations in London between the government of the United Kingdom and plenipotentiaries of Dáil Éireann. On 6 December 1921, they signed the Anglo-Irish Treaty, which led to the establishment of the Irish Free State, a dominion within the British Empire, from the twenty-six counties which had formed part of Southern Ireland. From the Constitution of Ireland in 1937, this became the state of Ireland, and left the British Commonwealth in 1949, following the implementation of the Republic of Ireland Act 1948. Under the terms of the Treaty, it remained a matter for the Parliament of Northern Ireland to decide whether become part of the Irish Free State, which it never did. The report of Boundary Commission in 1925 established under the Treaty did not lead to any alteration in the border.

While governments of Ireland, particularly under Éamon de Valera, declared themselves in favour of a united Ireland throughout the 20th century, the prospect of a united Ireland assumed particular importance following the outbreak of the Troubles in Northern Ireland in the late 1960s. All major political parties in Britain and in both parts of Ireland now accept the principle that a united Ireland can be achieved only with the consent of the majority of the people of Northern Ireland, known as the principle of consent. Sinn Féin (who were associated with the main Irish republican paramilitary group, the Provisional IRA, during the Troubles) favour a united Ireland, as does the Social Democratic and Labour Party (SDLP) in Northern Ireland. In 1999, Articles 2 and 3 of the Irish constitution were amended to abandon the Republic's territorial claim on Northern Ireland, although it still refers to itself officially as 'Ireland'.

Unionist Context

A united Ireland outside of the UK has long been opposed by all unionist and Ulster loyalist parties. This opposition initially manifested itself in an electoral repudiation, particularly in Ulster and also in parts of Dublin, of the Home Rule party in the late 19th Century.

In the Government of Ireland Act 1920 the Unionists in Northern Ireland achieved constitutional recognition with the creation of their own elected Parliament controlling the home affairs of 6 counties of Ulster while control of foreign and defence policy rested, as before, in Westminster.

The UK government is currently committed under the Northern Ireland Act 1998 to following the wishes of the majority of the Northern Ireland population, a position accepted by all other signatories to the Good Friday Agreement and which status is also enshrined in the Irish constitution by a referendum held in the Republic of Ireland in 1998.

In demographic terms, the six counties of Northern Ireland taken as a whole contain a majority of Ulster Protestants who almost all favour continued union with Great Britain, although individually four of the six counties have Irish Catholic majorities and majorities voting for Irish nationalist parties. The religious denominations of the citizens of Northern Ireland are only a stereotypical guide to their likely political preferences, as there are both Protestant nationalists and Catholic unionists. Surveys identify a significant number of Catholics who favour the continuation union without identifying themselves as unionists or British.

Unionist paramilitary groups have opposed a United Ireland since the early 1900's.

Recent immigrants to Ireland, and their descendants, some of whom are neither Catholic nor Protestant, have differing views on the issue. However only those with UK or Irish Citizenship, and who are resident in NI, have a vote on the matter.

Kings and High Kings

Before the coming of the Normans, there existed the title of Ard Rí (High King), usually held by the Uí Néill, but this was more of a ceremonial title denoting a sort of "first among equals", rather than an absolute monarchy and unitary state as developed in England and Scotland. Most were described in the records as king "with opposition". Nevertheless, several strong characters imbued the office with real power, most notably Máel Sechnaill mac Maíl Ruanaid (845–860), his son Flann Sinna (877–914) and Flann's great-grandson Máel Sechnaill mac Domnaill (979–1002; 1014–1022), Brian Boru (1002–1014), Muircheartach Ua Briain (1101–1119), and Toirdhealbhach Ua Conchobhair (1119–1156).

What prevented the consolidation of truly national power even by the Ard Rí was the fact that the island was divided into a number of autonomous, fully independent kingdoms ruled by rival dynasties. The most powerful of these kingdoms in the immediate pre-Norman era were Aileach, Brefine, Mide, Leinster, Osraige, Munster and Connacht. In addition to these, there were a number of lesser subject kingdoms such as Airgialla, Uladh, Brega, Dublin, Desmond, and Uí Maine. Many of these kingdoms and lordships retained, at the very least, some degree of independence until the 17th century.

In 1168–72, the Norman invasion of Ireland ended with the acceptance by some of the Gaelic kings and bishops of the unitary rule of Henry Plantagenet as Lord of Ireland. In 1297 the first Parliament of Ireland sat, modelled on the Norman–English parliament but only representing large landowners and merchants. However, by 1300 the Norman system was breaking down and Norman lords and the former Gaelic dynasties reasserted local control in their areas. By 1500 the area directly controlled by the Lordship had reduced to the Pale. The power of the lords deputy had become similar to the former high kings "with opposition", and they could only succeed in alliances with the local dynasties.

Under King Henry VIII, the Tudor conquest of Ireland included the establishment of the Kingdom of Ireland in 1541–42. The dynasties were to be included in the system and use English law, and the process took decades of treaty negotiations and wars, ending with the Plantation of Ulster that started in 1607.

Confederate Ireland 1642–49

The next significant moment occurred in 1642 when the Confederate Association of Ireland – an Irish Catholic government formed to fight the Irish Confederate Wars, assembled at Kilkenny and held an all-Ireland assembly. The Confederates did rule much of Ireland up to 1649, but were riven by dissent in later years over whether to ally themselves with the English and Scottish Royalists in the Wars of the Three Kingdoms. Ultimately, they dissolved their Association in favour of unity with the Royalists, an alliance that was in an agreed upon return for religious toleration and political autonomy for Ireland. The royalists however were defeated in the Cromwellian conquest of Ireland, and from 1653 to 1660 Ireland was united for the first time under a British parliamentary government, ruling from London.

1653–1921

Although ruled by Britain, Ireland was a united political entity from the end of the Wars of the Three Kingdoms in 1653 until 1921. Until the Constitution of 1782, Ireland was placed under the effective control of the British-appointed Lord Lieutenant of Ireland due to restrictive measures such as Poynings' Law. From 1541 to 1801, the island's political status was that of the Kingdom of Ireland in personal union with the English (and later the British) Crown. Under the leadership of Henry Grattan, the Parliament of Ireland (still dominated by the Ascendancy) acquired a measure of autonomy for a time. After the UK Act of Union, of 1800, Ireland became part of the United Kingdom of Great Britain and Ireland, a single entity, with the act removing the powers of the Parliament of Ireland, upon which time only one, consolidated, UK Parliament sat in London.

Ireland was last undivided at the outbreak of World War I after national self-government in the form of the Third Home Rule Act 1914, won by John Redmond leader of the Irish Parliamentary Party was placed on the statute books, but suspended until the end of the war. It was amended to partition Ireland for six years following the objections of Irish Unionists.

In the Irish general election, 1918, the republican Sinn Féin political party won the vast majority of seats in Ireland. The newly elected Sinn Féin candidates did not take their seat in Westminster; instead they formed a republican assembly in Dublin called Dáil Éireann which declared Irish independence in January 1919. Its claims over the entire island were, however, not accepted by northern Unionists. Under the Anglo-Irish Treaty the Irish Free State became in 1922 the name of the state covering twenty-six counties in the south and west, replacing the Irish Republic, while six counties in the northeast remained within the United Kingdom under the Government of Ireland Act 1920. According to some historians, Sinn Féin had no special policy towards Ulster despite its different religious and political make-up, regarding it as an integral part of an Irish republic.

By the end of the First World War, several moderate unionists came to support the Home Rule movement, believing that it was the only way to keep a united Ireland in the United Kingdom. The Irish Dominion League opposed partition of Ireland into separate southern and northern jurisdictions, while arguing that the whole of Ireland should be granted dominion status with the British Empire.

1922–98

In 1925, the Boundary Commission that was established to fix the future line of the border had to be rescued by an intergovernmental deal signed on 3 December. Essentially the Irish Free State's share of the UK national debt was waived by Britain in exchange for the border remaining as defined in the 1920 Government of Ireland Act. Winston Churchill told the Irish High Commissioner to the United Kingdom in 1946: "I said a few words in parliament the other day about your country because I still hope for an united Ireland. You must get those fellows in the north in, though; you can't do it by force. There is not, and never was, any bitterness in my heart towards your country". He later said "You know I have had many invitations to visit Ulster but I have refused them all. I don't want to go there at all, I would much rather go to southern Ireland. Maybe I'll buy another horse with an entry in the Irish Derby". Subsequently, but without reference to the financial aspect of the deal, the Free State, and its successor, the Republic of Ireland (declared in 1949), both claimed that Northern Ireland was part of their territory, but did not attempt to force reunification, nor did they claim to be able to legislate for it. Nevertheless Article 15.2 of the Constitution of Ireland (enacted in 1937) provided for the possibility of devolution within the present unitary Irish state, originally intended to absorb the old Parliament of Northern Ireland institutions.

Tensions between republican and loyalist groups in the north erupted into outright violence in the late 1960s. The British government deployed troops in the area under Operation Banner, and the force became engaged in a thirty-year factional conflict that claimed approximately 3,500 lives. During the period, the parliament of the United Kingdom abolished Stormont and introduced direct rule. Rule at Stormont would be restored following the 1998 Good Friday Agreement and concurrent peace process. With the agreement in place, the Republic voted to amend Articles 2 and 3 of its constitution so that territorial claims were amended with recognition of the Northern Ireland people's right to self-determination.

1998-2016

Both the Irish and British governments created a number of all-island bodies and services, such as the all-island electricity network from November 2007, followed by the all-island gas network. Besides these services, governmental bodies such as The Loughs Agency, Waterways Ireland, InterTradeIreland and the North/South Ministerial Council have been set up; with more planned in the near future. Recently, politicians have called for there to be an all-island corporation tax of 12.5% (currently the Republic's corporation tax – the lowest in the European Union), to boost Northern Ireland's economy. Other politicians have called for an all-island telecommunications network, especially within regard to mobile phones. The Irish government are currently investing over €1 billion in Northern Ireland as well, especially in the West, around Derry. Investments include upgrading City of Derry Airport (at a cost of €11 million), building a Letterkenny/Derry–Dublin motorway or high-quality dual carriageway, reopening the Ulster Canal, and improving cancer services in the region for those in the region itself, but also people from County Donegal in the Republic.

Present day

The leading political parties in the Republic of Ireland, Fianna Fáil and Fine Gael have often made a united Ireland a part of their political message. It is also a main focus of Sinn Féin in both the Republic of Ireland and Northern Ireland and the Social Democratic and Labour Party (SDLP) in the latter. In contrast, the Unionist community – composed primarily of Protestants in the six counties that form Northern Ireland – opposes unification. All of the island's political parties (except for tiny fringe groups with little electoral representation) have accepted the principle of consent, which states that Northern Ireland's constitutional status cannot change without majority support in Northern Ireland.

Many Unionist Protestants in Northern Ireland argue they have a distinct identity that would be overwhelmed in a united Ireland. They cite the decline of the small Protestant population of the Republic of Ireland since independence from the United Kingdom, the economic cost of unification, their place in a key international player within the UK and their mainly non-Irish ancestry. Unionist people in Northern Ireland primarily find their cultural and ethnic identity from the Scottish and English planters, whose descendants can be found in the three counties of Ulster which are governed by the Republic of Ireland. Such individuals celebrate their Scots heritage each year like their counterparts in the other six counties. While Catholics in general consider themselves to be Irish, Protestants generally see themselves as British, as shown by several studies and surveys performed between 1971 and 2006. Many Protestants do not consider themselves as primarily Irish, as many Irish nationalists do, but rather within the context of an Ulster or British identity. A 1999 survey showed that a little over half of Protestants felt "Not at all Irish", while the rest "felt Irish" in varying degrees.

Given that all significant political parties and both the UK and Irish governments support the Principle of Consent the final choice is one for the people of Northern Ireland, alone, to decide. Meanwhile, in certain instances there is already a degree of Irish unity. For example, the Church of Ireland and the Roman Catholic Church are both organised on an all Ireland basis. The Irish rugby football, cricket and international rules teams are drawn from both north and south. Members of the Irish Defence Forces and the Irish Guards regiment in the British Army are drawn from north and south of the border.

Following the United Kingdom European Union membership referendum, 2016, Irish politicians began the discussion regarding possible changes to the border between Northern Ireland and the Republic of Ireland. There are several key issues related to the United Kingdom withdrawal from the European Union, including the establishment of a new external border of the European Union, or the withdrawal of access, to Northern Ireland, of the regional development assistance scheme (and new funding thereof) from the European Union. Sinn Féin has used these concerns, which saw the North vote majority "Remain" in the referendum, as the basis for new discussion on possible unification in the future. These calls were rejected by the British government and Unionist politicians, with Theresa Villiers arguing that there was no evidence that opinion in the North had shifted towards being in favour of a united Ireland. However, the Northern Ireland Assembly election, 2017 saw major gains by Irish nationalist parties such as Sinn Fein, which took advantage of those gains to call for a Northern Ireland referendum on UK exit.

The Brexit Secretary, David Davis, confirmed to Mark Durkan, the SDLP MP for Foyle, that Northern Ireland can leave the United Kingdom and join the European Union as part of the Ireland after Brexit and that it would not have to then reapply for EU membership, if it voted for reunification. Such a change would have to take place in accordance with Article 3.1 of the Constitution of Ireland and the Northern Ireland Act 1998.

Northern Ireland

Opposition to reunification comes mainly from Unionist political parties in Northern Ireland, particularly the Ulster Unionist Party and the Democratic Unionist Party. It also comes from loyalist paramilitary groups such as the Ulster Defence Association and Ulster Volunteer Force.

Nationalist parties in Northern Ireland support the independence of Northern Ireland (and of Ireland as a whole) from the United Kingdom and all nationalist parties support a united Ireland in some form. Sinn Féin is currently the largest nationalist party in the Northern Ireland Assembly (and the third largest in the Dáil). Until recently, it had a policy of violent intervention through the Provisional Irish Republican Army but since the mid-90s had adopted a policy of achieving a united Ireland through constitutional means only. It supports integration of political institutions across the island of Ireland. For example, the party has proposed that Northern Ireland should have some form of representation in the Dáil, with elected representatives from either the Northern Ireland Assembly or the British House of Commons able to participate in debates, if not vote. The major parties in the Republic have rejected this notion on a number of occasions. Should Irish reunification ever occur, Sinn Féin has stated that it would wish to amend the Irish constitution to protect minorities, including the Protestant and Ulster Scots communities, that are already protected by the European Convention on Human Rights.

The Social Democratic and Labour Party had previously been the largest nationalist party in Northern Ireland, but has suffered in elections since Sinn Féin abandoned armed politics. As with Sinn Féin, it is committed to achieving a united Ireland. However, throughout its history, it has believed that reunification should be accomplished through constitutional means only. It would support a united Ireland only if a majority of both parts of Ireland voted for it in a referendum. In a united Ireland, the SDLP would support the continuation of a devolved Northern Ireland, governed by a local assembly. Aside from the major parties, Northern Ireland has several minor Nationalist parties. Among these, some parties are tied to paramilitary organisations and seek the reunification of Ireland through armed politics. These include the Irish Republican Socialist Party, which supports a united socialist Irish state and is affiliated with the Irish National Liberation Army. Another such party, Republican Sinn Féin, linked to the Continuity IRA, does not believe that the Irish government or the Northern Ireland Executive are legitimate as neither legislates for Ireland as a whole. Its Éire Nua (in English, New Ireland) policy advocates a unified federal state with regional governments for the four provinces and the national capital in Athlone, a town in the geographic centre of Ireland. None of these parties has significant electoral support.

Republic of Ireland

Historically the largest party in the Republic, and the governing party for most of the last 80 years, Fianna Fáil has supported reunification since its foundation, when it split from Sinn Féin in 1926 in protest at the party's policy of refusal to accept the legitimacy of the partitioned Irish state. However, in its history since, it has differed on how to accomplish it. Fianna Fáil rejected the 1985 Anglo-Irish Agreement, which gave the Republic of Ireland an advisory role in Northern Ireland, claimed the agreement was in conflict with the then Articles 2 and 3 of the Constitution of Ireland because it recognised Northern Ireland as part of the United Kingdom. It later oversaw the removal of these articles from the constitution and today fully supports the Good Friday Agreement, which it negotiated in coalition with the Progressive Democrats (see below). On 17 September 2007 Fianna Fáil announced that the party would, for the first time, organise in Northern Ireland. Ahern said that, "it is time now for this Party to play its full role, to take its proper place, in this new politics – in this New Ireland." By 2009 Martin Mansergh accepted that a united Ireland was not a major priority.

Historically, the second-largest party and, following the 2011 General Election, the largest party in the Dáil, Fine Gael, a descendent of the pro-Anglo-Irish Treaty section of Sinn Féin upon the partition of Ireland, has also supported reunification as one of the its key aims since its foundation. It supports the Good Friday Agreement and had previously negotiated the Anglo-Irish Agreement.

The Labour Party, likewise, has also supported reunification since the foundation of the state, although it has always considered this aim secondary to social causes. It also fully supports the Good Friday Agreement, and supported the Anglo-Irish agreement. The former President of Ireland, Mary Robinson, resigned from the Irish Labour Party because she objected to the exclusion of unionists from the talks that led to the 1985 agreement.

The now defunct Progressive Democrats, a liberal party, which split from Fianna Fáil in the mid-1980s, supported reunification since its foundation, but only when a majority of the people of Northern Ireland consent to it. The party fully supported the Belfast Agreement. Former party leader, Mary Harney, was expelled from Fianna Fáil for supporting the Anglo-Irish agreement. The party was one of the key negotiators of the Belfast Agreement.

The Green Party support the full implementation of the Good Friday Agreement, which takes the possibility of Irish unification into account as the basis of simultaneous referendums on the issue being successful in the Republic and in Northern Ireland. The Green Party are active in both the Republic and Northern Ireland. It currently has two TDs and one senator in the Oireachtas and two MLAs in Stormont.

Sinn Féin is also an active party in the Republic, where its policies towards a united Ireland are the same as in Northern Ireland.

Great Britain

In Great Britain, all major parties support the Good Friday Agreement.

Historically, there has been support for a united Ireland within the left of the Labour Party, and in the 1980s it became official policy to support a united Ireland by consent. The policy of "unity by consent" continued into the 1990s, eventually being replaced by a policy of neutrality in line with the Downing Street Declaration. The current Labour leader Jeremy Corbyn personally supports a united Ireland, although he has said that it is "up for the Irish people to decide" whether to remain part of the UK.

The Conservative Party has traditionally taken a strongly unionist line in relation to the United Kingdom as a whole by opposing nationalism in Scotland and Wales as well as Northern Ireland. Until 1974 they had a parliamentary alliance with the Ulster Unionist Party and the two parties retained formal ties until 1985. The Conservatives' current position is to "[work] in Northern Ireland to restore stable and accountable government based on all parties accepting the principles of democracy and the rule of law."

The Liberal Democrats have a close relation with the Alliance Party of Northern Ireland and share their policy of supporting the Good Friday Agreement whilst expressing reservations about what they perceive as its institutionalised sectarianism.

In Northern Ireland

Opinion polls of the Northern Ireland population have consistently shown majorities opposed to a United Ireland and in support of Northern Ireland remaining part of the United Kingdom. For example, in a November 2015 survey RTÉ and the BBC, 30% of the population expressed support for a United Ireland in their lifetime with 43% opposed and 27% undecided. However, when asked about the status of Northern Ireland in the short-to-medium term, support for unity was lower at around 13% of the population. The 2013 annual Northern Ireland Life and Times survey conducted by the Queen's University Belfast and Ulster University found that a united Ireland was the favoured long term option of 15% of the population while remaining part of the United Kingdom was the favoured long term option of 66% of the population. When the same survey was carried out in 2015, support was 22%.

In 1973, the population of Northern Ireland was granted a referendum on whether Northern Ireland should remain part of the United Kingdom or join with the Republic of Ireland to form a united Ireland. The result was 98.9% in favour of union with the rest of the UK, but the poll was overwhelmingly boycotted by nationalists, and the turnout was therefore 58.7%. The pro-UK vote did however represent 57.5% of the entire electorate, notwithstanding the boycott.

A possible referendum on a united Ireland was included as part of the terms of the Good Friday Agreement. Currently about 40% of the Northern Ireland electorate vote for Irish nationalist parties that oppose the union with Great Britain and support a united Ireland as an alternative, although it is not the only issue at election time so it is difficult to take this figure as a direct indication of levels of support for a united Ireland.

A 2011 survey by Northern Ireland Life and Times found that 52% of Northern Irish Catholic respondents favoured union with Great Britain over a united Ireland. This is despite the fact that most Catholics who vote do so for political parties that are Nationalist.

Since Brexit, support for reunification has increased, with 22% of respondents favourable towards reunification, up from 17% in 2013. 43% of Catholics would now back reunification, up from 35% in 2013. According to this survey, support for a referendum stands at 53% of Catholics, while 72% of Protestant respondents were opposed to the idea.

In 2013 an Ipsos Mori poll asked "If there was a referendum tomorrow would you vote for...?" and the answers for different regions of Northern Ireland were as follows,

The same poll recorded answers from people in different age groups as follows.

Answers from people of different religious backgrounds were as follows.

Another opinion poll of 1,089 people conducted by LucidTalk in 2014 around the time of the Scottish Referendum posed several questions, one of which was "If a referendum on Irish Unity was called under the Good Friday Agreement would you vote: Yes for unity as soon as possible, Yes for unity in 20 years, or No for Northern Ireland to remain as it is". The results were as follows.

In the Republic of Ireland

Support for Irish unity is a feature of all major political parties in the Republic of Ireland. Some very small pressure groups do exist, such as the Reform Movement and lodges of the Orange Order in the Republic of Ireland, that are sympathetic to Northern Ireland remaining within the UK for the foreseeable future, but their impact on the broader political opinion is negligible. A Dublin riot in 2006 prevented a march organised by "Love Ulster", though the rioters did not have a wide support base. A minority of politically conservative Catholic writers from the Republic of Ireland, such as Mary Kenny and Desmond Fennell have expressed misgivings about a united Ireland, fearing the incorporation of a large number of Protestants would threaten what they see as the Catholic nature of the Republic. A Red C/Sunday Times poll in 2010 found that 57% are in favour of a united Ireland, 22% say they are opposed, while 21% are undecided. A 2006 Sunday Business Post survey reported that almost 80% of voters in the Republic favour a united Ireland: 22% believe that "achieving a united Ireland should be the first priority of the government" while 55% say they "would like to see a united Ireland, but not as the first priority of government." Of the remainder 10% said no efforts should be made to bring about a united Ireland and 13% had no opinion. This poll was markedly up from one year earlier when a Sunday Independent article reported that 55% would support a united Ireland, while the remainder said such an ambition held no interest.

In October 2015 an opinion poll commissioned by RTÉ and the BBC and carried out by Behaviour & Attitudes asked those in the Republic of Ireland the question "There are a number of possible options for the constitutional status of Northern Ireland. In the short to medium term, do you think Northern Ireland should…" with the following responses,

The same poll also asked "Thinking of the long-term policy for Northern Ireland, would you like to see a united Ireland in your lifetime?" with the following responses,

The poll then asked a further question concerning the influence of the tax consequences of a united Ireland on support for it,

In Great Britain

There has been significant support in Great Britain for Ireland to reunify as a political entity. The last British Social Attitudes Survey to ask the question in 2008 found that 34.94% supported Irish reunification while 44.30% supported Northern Ireland remaining part of the UK. The poll was run 19 times between 1983 and 2007, with each result being in favour of Irish unity, then again in 2008 with the result being against Irish unity for the first time. The highest support for unity came in 1994 with 59.36% of the respondents supporting Irish reunification, while 24.09% supported Northern Ireland remaining in the UK.