Why did the Conservatives stay in power from 1951 - 1964?

A variety of factors have to be identified in order to adequately answer this question either arguede to have been working in concert with equal import or with one or two argued to have greater significance. Firstly, there was a lack of a clear alternative in successive elections as the Labour party was suffering from constant infighting and struggling to present itself as a well-managed and cohesive government-in-waiting. The deaths of members high up in the party, such as Aneurin Bevan also hindered the Labour election hopes. 

By contrast, the Conservatives were often led by charismatic and capable leaders who deftly timed their elections at points which would favour their electoral chances. In addition to this, the Conservative Party was presiding over a period of prosperity and the aspirations of the people were being met under their leadership with record levels of employment and consumerism now available to a contented public. This also ties into the 'post-war concensus' whereby the Conservatives agreed to maintain many of the much admired socialist aspects of the the Atlee government with a few of their own policies.