...over a failed Dunkirk evacuation or whatever, what do they do afterwards? Assuming this does not change the general course of the war (Germany attacks the U.S.S.R. in 1941), would they re-enter the war at some point, a bit like what happened after the Treaty of Amiens in the early 19th century? I'd be willing to say that they would, but I'd like to hear your opinions.
Also, could someone chime in on whether or not the 1940 General Election would have been held in this situation? If so, what would have been the probable result?