The whole idea that Veulling or any other IAG owned company could just come in and replace BA shorthaul is contrary to the spirit of UK employment law, however BALPA are petrified that BA would find a way
I don't think BALPA are petrified that "BA would"... Why would BA (whatever "BA" is??) give it's work away?
BALPA may well be concerned that
IAG might transfer the work to Vueling, as is their right. Not sure UK employment law would have anything to do with it?