Historically the Labour party has had a left and a right wing with the latter usually in the ascendancy. Much of that was down to the trade unions being led by moderates who were happy to use their block votes at Labour conference and in elections to the ruling National Executive Committee in favour of a leadership committed to a social democratic programme. In the immediate post-war period the leaders of the major unions (the Transport workers, Engineers, Miners and Railway workers) all had much more in common with Methodism than Marx. The landslide General Election victory of 1945 brought to power a majority Labour government for the first time and although its MPs sang the red flag in the commons the reality was that Attlee’s administration was a reforming not a revolutionary one.
At the time some thought that with its overwhelming parliamentary majority Labour would be in power for a long time but it was not to be. A cabinet which included left wingers Cripps and Bevan stayed united for a time seeing through a number of nationalisations and the creation of a National Health Service but in 1950 the crunch came. It was then that the decision to introduce charges for NHS prescriptions and eyeglasses to fund involvement in the Korean war led to the resignation of Bevan and a young Harold Wilson from the cabinet. From then on Nye, as he was affectionally known by his supporters, started to position himself as leader of the left.
It was, however, a left that believed in a parliamentary route to socialism, attempts by pro-communist elements to influence the party were dealt with decisively without any protest from Bevan and his allies. Electoral defeat in 1951 was followed by a sustained period of internal civil war but it was the right who won with Hugh Gaitskell succeeding Attlee as leader and Bevan giving up the fight returning to the shadow cabinet following his high profile renunciation of unilateralism at the 1957 conference, eventually becoming Deputy Leader shortly before his death from cancer.
Gaitskell who also died prematurely was succeeded by Wilson who by then had also made peace with the Labour establishment. Wilson got the leys to number 10 after thirteen years of Tory rule in 1964 and like Attlee he included in his cabinet key left wingers. In the 1960s infiltration by communists had given way to similar tactics by the Trotskyist Socialist Labour League which had got control of the party’s youth section. They were expelled en masse with the approval of a certain Tony Benn then a newish member of the NEC. By 1970 Labour was out of office and Michael Foot emerged as the prominent figure on the left of the party.