In e.g. Sweden, the communists stooped being Stalinists when Moscow told them that Stalin was bad... They did start to critizise the Eastern block dictators early... about 1990!
(There were also anarchists etc, but in general the non-communist extreme left-wingers were few before ~1968, when they got more numerous and varied).
Also, I remember reading surprise after 1989 on how much control Soviet had over the West European communist parties. E.g. that the Italian communist party had such an accomodating attitude by order (Soviet wanted to get a de facto split in Western/Eastern Europe.)
