Maybe 'mikeovswinton' was onto something about Billy Connolly's political past if this old quote from today's Observer is anything to go by:
ON HIS SUBSEQUENT FRIENDSHIP WITH PRINCESS ANNE 'I'm not going to throw away the hand of friendship to suit 100 Trotskyites in Glasgow' (1989)
Referring to the Peasants of Leon as Trotskyites rather than as Trotskyists is usually a giveaway that Uncle Joe was once a family friend but radical politics was always a bit different in Glasgow.
I don't have the quote immediately to hand but I do remember reading about the late SPGBer, Alec Shaw, who would apparently rip into the 'Communist Blatherskites and Trotskyite Gobshites' - I'm paraphrasing (slightly) - from the Party platform in Glasgow in the 40s and 50s.
And by all accounts, that debate between Solidarity's Ken Weller and the IS's Paul Foot in '68 did get rather acrimonious. You'd be surprised by how many people can still hold onto the grudges long after they drop the politics.
Anyway, check out Connolly's 'Did I Say That?' column. If nothing else, it's a good timeline for showing how Connolly lost his comedy mojo a long, long time ago.