It is hardly surprising that the Labour Party and the unions ended up as the firmest supporters of state capitalism. Trade unions do not exist to change society, they are to get a larger slice of the capitalist cake, not take over the bakery. Indeed, without the buying and selling economy, based on wage labour, there is no role for a trade union. With no role for a trade union, there is no job for a union official. However, the power, privileges and status of the union bureaucrats are very much determined by how much their status is recognised by the capitalist class. To protect their position, it is natural for unions to look for a more regulated capitalism, a capitalism based on partnership between employers and labour organisations. It was to achieve this that the Labour Party was set up in the first place./
Their position was recognised and they were welcomed as junior partners in the state machine during the First World War. It was a logical step for them to go beyond mere regulation and favour full blown state ownership, with the state as the major employer working in partnership with the unions. Thus Clause Four was adopted as a means of selling this to the working class at the same time as the Unions’ control over the party was established. Their function as part of the state machine was re-emphasised during the Second World War, and continued afterwards with the various tripartite commissions, quangos like the National Economic Development Corporation, and the routine appointment of Trade Union General Secretaries to the House of Lords./
As part of the state wanting more state control the party attracted to itself those sections of the ruling class who would benefit from it. This helps explain the number of lawyers and other professionals in the Attlee governing party. By the 1940s even the leaders of the party came from this social group.
In 1951 there was another General Election. This time Labour lost. It was followed by 13 years of Tory government.
So that answers your question about the Atlee government.
source