If you want to read a Canadian perspective on this, CBC has an article on this exact thing.

If I were him (which I’m not), I wouldn’t appear before any political panels after what they did to him the first thing. All the panellists want is sound bites to make him look bad.

Original source is The Independent

They mention in the US they are affiliated with the US branch of Communications Workers of America (CWA). “Separately, the WWU-UK branch has affiliated with United Tech and Allied Workers (UTAW), a national branch of the Communication Workers Union (CWU).” You can see their FAQ for more details.