* The door-knocking campaigning teams:
Couldn't find one for Ukip, locally. Presumably they do their campaigning comms behind closed apps.
* Some long-standing Facebook Groups, easily found:
Momentum are the extreme-left sect of Corbyn supporters who now dominate the national Labour Party, reportedly a feuding mix of Trotsykites and Stalinists with perhaps a few lurking Maoists keeping their heads down.