The Labour Party is considered to be left of centre. It was initially formed as a means for the trade union movement to establish political representation for itself at Westminster. It only gained a 'socialist' commitment with the original party constitution of 1918. That 'socialist' element, the original Clause IV, was seen by its strongest advocates as a straightforward commitment to the "common ownership", or nationalisation, of the "means of production, distribution and exchange". Although about a third of British industry was taken into public ownership after the Second World War, and remained so until the 1980s, the right of the party were questioning the validity of expanding on this objective by the late 1950s. Influenced by Anthony Crosland's book, The Future of Socialism (1956), the circle around party leader Hugh Gaitskell felt that the commitment was no longer necessary. While an attempt to remove Clause IV from the party constitution in 1959 failed, Tony Blair, and the 'modernisers' saw the issue as putting off potential voters, and were successful thirty-five years later, with only limited opposition from senior figures in the party.

What year did the Conservative Party gain a socialist commitment?