Manning was educated at Ardingly College and went on to study at Oriel College, Oxford, and at the Paul H. Nitze School of Advanced International Studies of the Johns Hopkins University. He began his career as a civil servant in the Foreign and Commonwealth Office (FCO) in 1972. He has served in UK Embassies in Warsaw, New Delhi, Paris, and Moscow, and within the FCO he has worked on the Central American desk, the Russian desk and held several senior positions. He has represented the UK in Brussels and also at the International Conference on the former Yugoslavia in 1994.
Between 1995 and 1998, he was British Ambassador to Israel; from 2001, he was a foreign policy adviser to British Prime Minister Tony Blair. During this time he developed a close relationship with his counterpart, then US National Security Advisor Condoleezza Rice. Blair selected him to replace Christopher Meyer as the British Ambassador to the United States. Manning took up the post in 2003. Ambassador Manning visited numerous states, as well as the US territory of Puerto Rico, during his term as Ambassador to the United States and was instrumental in planning Queen Elizabeth's most recent visit.
In the weeks before the United States-led invasion of Iraq, as the United States and Britain pressed for a second United Nations resolution condemning Iraq, President Bush met with Tony Blair. During a private two-hour meeting in the Oval Office on 31 January 2003, Bush made it clear to Prime Minister Tony Blair of Britain that he, Bush, was determined to invade Iraq without the second resolution, or even if international arms inspectors failed to find unconventional weapons, stated a confidential memo about the meeting written by Manning and reviewed by The New York Times.
At their meeting, Bush and Blair candidly expressed their doubts that chemical, biological or nuclear weapons would be found in Iraq in the coming weeks, the memo said. The president spoke as if an invasion was unavoidable. The two leaders discussed a timetable for the war, details of the military campaign and plans for the aftermath of the war. The memo also says the president raised three possible ways of provoking a confrontation, including the most controversial:
"The U.S. was thinking of flying U2 reconnaissance aircraft with fighter cover over Iraq, painted in U.N. colours," the memo says, attributing the idea to Mr. Bush. "If Saddam fired on them, he would be in breach".
His close relationship with the Prime Minister suggests he has been a key figure in driving British foreign policy in respect of the United States, particularly in the aftermath of the 11 September 2001 attacks and the decision to invade Iraq.
On 30 November 2009, Manning gave evidence to The Iraq Inquiry.
He was appointed Knight Grand Cross of the Order of St Michael and St George (GCMG) in the 2008 New Year Honours. Manning retired from HM Diplomatic Service in January 2008. Six months later, he joined BG Group (formerly British Gas plc) on a part-time basis at a reported annual salary of £80,000. In 2008 he became a non-executive director of Lockheed Martin, the multinational arms manufacturer that made millions supplying military hardware for the war, and joined the advisory board of Hakluyt & Company, an intelligence company partly staffed by former SIS officers.
At the beginning of 2009, Manning was appointed by The Queen to a "part-time, advisory role" in the newly formed Household of Prince William of Wales and HRH Prince Henry of Wales, since renamed after the marriage of Prince William to Catherine Middleton, the now Duchess of Cambridge now known as the Household of the Duke and Duchess of Cambridge and Prince Harry.
Manning has been elected to the Council of Lloyd's as an external member.
In 2010 Manning formed Gatehouse Advisory Partners Limited (http://www.gatehouseadvisorypartners.com) in partnership with Sir Jeremy Greenstock. Gatehouse works with organisations to factor geopolitics into their decision making.
He was appointed Knight Commander of the Royal Victorian Order (KCVO) in the 2015 New Year Honours.1972: entered Foreign and Commonwealth Office
1972–1974: Foreign and Commonwealth Office (Mexico/Central America Department)
1974–1977: Warsaw, Poland (3rd later 2nd Secretary)
1977–1980: New Delhi, India (2nd later 1st Secretary)
1980–1982: Foreign and Commonwealth Office (Soviet Department)
1982–1984: Foreign and Commonwealth Office (Deputy Head of Policy Planning Department)
1984–1988: Paris, France (1st Secretary)
1988–1990: Counsellor on loan to Cabinet Office
1990–1993: Moscow, Russia (Counsellor, Head of Chancery)
1993–1994: Foreign and Commonwealth Office (Head of Eastern Department)
1994: UK member of Contact Group on Bosnia (International Conference on Former Yugoslavia)
1994–1995: Foreign and Commonwealth Office (Head of Policy Planning Staff)
1995–1998: Tel Aviv, Israel (Ambassador)
1998–2000: Foreign and Commonwealth Office (Deputy Under-Secretary)
2001: UK Delegation NATO Brussels (Ambassador)
2001–2003: Foreign Policy Adviser to the Prime Minister
2003–2007: Washington, USA (Ambassador)
Knight Grand Cross of the Order of St Michael and St George (GCMG) – 2008
Knight Commander of the Royal Victorian Order (KCVO) – 2015, CVO - 2007