Marlborough by election, 1970

The Marlborough by-election of 1970 was a by-election for the electorate of Marlborough, held on 21 February 1970 during the 30th New Zealand Parliament. The by-election resulted from the death of Tom Shand on 11 December 1969, only 12 days after he (and the government) had been re-elected on 29 November; and the new National candidate was defeated by the greatest swing against a government since the 1935 general election, in what was a largely rural electorate generally regarded a safe National seat. Tom Shand had held the seat from 1946, when he defeated Labour’s Edwin Meachen.

The defeated National candidate Anthony Shand was the son of the previous member, and there was some criticism of him for frequent "butting-in" during a combined television broadcast appearance for all the candidates on Wednesday 17 February.

The vote for Tom Shand had been close in 1966. Labour only decided that the seat was winnable in January, and sent in two MPs Arthur Faulkner and Colin Moyle to organise the campaign. Labour’s candidate Ian Brooks was local; he was a senior clerk in the Picton manual telephone exchange and also had a small farm. The seat was largely rural, but Brooks polled particularly well in Picton, and well in the other two population centres, Blenheim and Kaikoura. The election-night margin to Labour of 1131 was so great that the final result was not expected to change when special votes, which generally tended to go to National, were counted. There were 32 informal votes.

George Chapman was the Wellington National Party chairman. He heard reports that all was not well in the campaign, the party was in deep trouble, and that Labour was making an all-out effort. But he found that party president Ned Holt was complacent about the by-election; saying that everything was in order, and that in any case National's majority in Marlborough was big enough to absorb any setback. But on by-election night Labour inflicted a stunning defeat on National, reducing the Government majority from six to four, and shaking party confidence. Chapman became the leader for change in the organisation, resulting in his nomination for party president in 1971, although he did not become president until 1973.