The Anti-Fascist Action were backed by the German Communist Party.
The Iron Front were set up by SocDems as an anti-communist alternative to AntiFa.
Because as we all know, the only way to fight disease is to oppose medicine and promote a homeopathic snake oil instead.
Every twentieth post of Working Class History is just anti communism. I wouldn't be surprised if they were Trots.
funnily enough i actually had the thought that they might be trots earlier today and went looking for evidence of such
didn't find anything explicit but i didn't get too deep into looking
Other posters here said they were Western anarchists, which might be the case.