PoD 44/45? Maybe Churchill suffering from a heart attack and being persuaded not to stand in the next election. Anthony Eden wins by a small majority.
Or maybe Labour don't have enough seats for a majority and have to form a coalition, Churchill refuses to serve as Deputy PM.
Going from hazy memory I remember reading somewhere that apparently one of the other major failings of the Conservative election campaign was that during war they didn't pay much attention to their regional and local party apparatus unlike Labour did whilst a part of the all-party coalition. That meant that when the election came around they had to start rebuilding whilst Labour was already fully organised. The other main problem was that whilst they like Churchill they were less keen on the Conservative party itself going on its policies in the 30s and the coalition had given Labour the opportunity to show they could handle government and their policies appealed more.
Considering how one sided our timelines results were I think you're going to be hard pressed to stop the Labour party from winning even with something like a double point of departure of the Conservatives keeping their local constituency party organisations running so ready to fight the election effectively, and have Churchill some disabled and forced to stand down so he doesn't make the silly statements he did. At best you'd probably get Labour winning but with a reduced majority so maybe less of a mandate to implement drastic reform or changes?
That might get you something to build on so that the Conservatives win a slim majority in the 1950 general election as opposed to Labour being re-elected with with a slim majority as in our timeline. The Conservatives were already elected back into government in 1951 so what would the extra year give us? Looking at the list of nationalised industries coal mining, the railways, road haulage, the canals, cable and wireless, the electricity and gas industries had all been nationalised but the steel industry wasn't taken over until 1951 apparently. An early election possibly avoid the government taking over the steel industry but that's all really.
None of this is really my area of expertise though so I'm more than happy to be corrected if I've misunderstood something.