I am a union member and I do not approve of any action taken that is not sanctioned by the whatever union one is a member of.

If as alledged, the European contractors are discriminating against British workers, then surely it would be provable and as such as illegal. I think it highly unlikely they have done anything illegal.

I think it more likely that these Wildcatters have been led by unsavoury sources of information. Some newspapers come to mind.