The Labour Party returned to power in Parliament on this day in 1945, winning an unprecedented – and largely unexpected - landslide victory after results were announced for the General Election held three weeks earlier.

The reason for the delay was to allow time for votes from serving soldiers to be delivered and counted – meaning that instead of finding out the result on the morning after the poll, parties were forced to endure an agonising wait.

Clement Attlee became Britain's new Prime Minister after Labour emerged from the election with a majority of 146 seats. His predecessor Winston Churchill tendered his resignation immediately; Mr Attlee was asked to form a new government by King George VI shortly afterwards.

Labour’s triumph was considered all the more surprising given Mr Churchill’s own personal standing, after inspiring the nation to victory in Europe as leader of the wartime coalition since May 1940.

Conservative candidate Winston Churchill campaigning with his wife Clementine in his constituency of Woodford.

The party increased its number of seats from 164 to 393, winning its first-ever overall majority in the Commons. More than 200 Conservative MPs were unseated; they and allied parties won 213 seats, the Liberals 12 and other parties 22.

[Read more: June 9, 1983 - Margaret Thatcher wins landslide second term as leftist Labour self-destructs]

The public responded to Labour’s manifesto promises of social reform including full employment, the creation of a National Health Service and the ‘welfare state’, at the same time rejecting the Conservatives’ pre-war record in domestic and foreign policy.

Mr Attlee, promising to raise standards of living not only for Britons but for people around the world, told the press: “I believe that the voting at this election has shown that the people of Britain are facing (a) new era with the same courage as they faced the long years of war."