"hate to sound like broken record, but one of the most significant reasons was that the working classes were no longer willing to support its continued enforcement. I think its significant that Churchill is not reelected near the end of WWII. "
Well, I am sympathetic to that, because the working class were by no means as sold on the Empire as has been made out subsequently. However, I think a lot of Kenyans, Irishmen, Tanganyikans, Singaporeans and Malay Chinese would be irritated to hear that the Empire was finished in 1945. Indeed in economic terms, imperial exploitation got worse just after the 2WW because the British sweated the Empire to generate the funds to pay for its balance of payments crisis. At the same time, actual investment there was tumbling, leading to the worst kind of brutalised plantation drudgery, all conducted at gunpoint. I once had the unfortunate experience of teaching a one-time overseer in Guyana, in an F.E. class, who boasted to me of having taken a whip to Cheddi Jagan, who went on to be Prime Minister.
The British Empire no longer ruled the waves after 1945, but it was a long time dying.