I really hope not, do BASSA / BALPA (Possible Lauren dispute) really want to screw BA over?? I suspect BALPA will have more sense in the end though.
I for one, along with most people at BA, would like a bonus this year, any strikes, or threat of them, will kill that. Look at the bigger picture, Open Skies is coming and if that is a success don't give the excuse to take work out of mainline in to that, if the unions cause BA grief then I am sure that could happen easily.