<P> The British Labour Party grew out of the trade union movement of the late 19th century, and surpassed the Liberal Party as the main opposition to the Conservatives in the early 1920s . In the 1930s and 1940s it stressed national planning, using nationalization of industry as a tool, in line with Clause IV of the original constitution of the Labour Party which called for the "...common ownership of the means of production, distribution, and exchange, and the best obtainable system of popular administration and control of each industry or service" (this clause was eventually revised in 1994). Labour has had several spells in government, first as minority governments under Ramsay MacDonald in 1924 and 1929--31 . MacDonald and half his cabinet split with the mainstream of the Party and were denounced as traitors . Labour was a junior partner in the wartime coalition from 1940--1945 . After the famous 1945 landslide under Clement Attlee (1945--51) it set up the welfare state with the National Health Service, nationalised a fifth of the economy, joined NATO and opposed the Soviet Union in the Cold War . Under Harold Wilson in 1964--70 it promoted economic modernisation . Labour was in government again in 1974--79, under Wilson and then James Callaghan . Escalating economic crises (the "Winter of Discontent") and a split with David Owen and others forming the SDP, resulted in Opposition status during the Thatcher years, 1979--1990 . </P> <P> Labour returned with a 179 - seat majority in the 1997 general election under the leadership of Tony Blair . The party's large majority in the House of Commons was slightly reduced to 167 in the 2001 general election and more substantially reduced to 66 in 2005 . Under Gordon Brown it was defeated in the 2010 general election, becoming the Opposition to a Conservative / Liberal - Democrat coalition . After further losses in the 2015 election party leader Ed Miliband resigned with the party in Opposition to a Conservative majority government under David Cameron . </P>

When did the labour party first come to power