In an evening of high political drama on this day in 1979, Prime Minister James Callaghan lost a parliamentary motion of confidence in his government by just a single vote, precipitating the downfall of his Labour administration.
The Conservative Opposition under leader Margaret Thatcher had tabled the motion of no confidence after the minority government had lost two seats in by-elections earlier in the month as well as the support of Scottish Nationalist MPs in the House of Commons.
Mr Callaghan’s government had survived another no confidence vote in December 1978 after securing the support of Ulster Unionist Party, but this time two key abstentions and the absence of one Labour MP from the vote through illness meant that it was defeated.
The Conservative motion was carried by 311 votes to 310, forcing the Prime Minister to ask the Queen to dissolve parliament "as soon as essential business (could) be cleared up", and set in motion a General Election.
Mr Callaghan had become leader of his party after the surprise resignation of Harold Wilson in 1976, beating Michael Foot and Roy Jenkins to the post. Within a year of him taking office, the narrow three-seat majority Labour had secured in the second General Election of 1974 was whittled away.
The minority government had managed to stay in power by negotiating the ‘Lib-Lab pact’ with Jeremy Thorpe’s Liberals in March 1977, which remained in force for 16 months, then through unofficial deals with the Ulster Unionists and Scottish Nationalists.
The Prime Minister had been widely expected to call an election in the autumn of 1978, but having not done so was critically damaged by ‘the Winter of Discontent’, a series of widespread strikes by public sector trade unions over the harsh winter of 1978-79.
After parliament was dissolved, a General Election was held on May 3 in which the Conservatives won with a majority of 44, making Mrs Thatcher the UK’s first female Prime Minister. Labour would not return to power for 18 years.