Its easy to forget that Attlee was Churchill's deputy during the ww2 and that the various labour leaders who led govt departments (Morrison, Gaitskell etc) or in opposition (e.g. Bevan) in ww2 established their legitimacy to govern post-war. Similarly When Churchil was re-elected back to power in 1951 he recognised that Attlee's government key achievements like the National Health service (whch Churchill had originally fiercly opposed) were for the benefit of the country and did not dismantle them. Attlee and Churchill in some respects had combination of both war and peace time leaders that isnt always recognised.

(Edit: clarity and spelling)