Thanks for the info, Alan!
I did not mean to get anyone upset by referring to trade unions. It was simply my experience as a union member (once) was quite an education for me; my little local had all sorts of agreements with trade unions in every corner of the world.
Had someone appeared at Union Hall with papers from their "allied" association back in Mongolia (or wherever), chances are the local would find some way to accomodate them as a "guest" member. This is somewhat different from the welcome an aspiring new apprentice recieves, BTW.
Politics aside, those who 'know the secret handshake' have a resource available to them that 'outsiders' do not.
One of the biggest hurdles to employment (for a non-citizen) can be the need to find a job before they come across the pond. I may be mistaken, but I believe a trade union is legally able to 'sponsor' someone, just as an employer can.
Not that I'm a shill for any union; I am not a union contractor ... and I bet I could find a way to put a Brit to work ... assuming he had the proper visa!