"Owain" wrote in message
. ..

I read recently that one-quarter of all workers in the construction
industry[1] in London/the SE are *illegal* immigrants; they aren't in
much position to complain. And they may be being paid only 30p an hour
in any case.

Wouldn't surprise me. But I still would have thought it good practice to
throw a packet of wall ties to them with the cement and blocks.