Flaps,
Promotion from F/O to Captain does not equal a payrise - yes you will be earning more money but it is NOT a rise. A rise is what you have just negotiated i.e. an increase to your basic salary in your present position.
I defy anyone on the council to give me a good reason why I got paid 90% of a Captain's salary during my first six months in command. All line captains do the same job and should get the same pay. Before you ask no I'm not in BALPA - I resigned over this very issue last year - I'd love to rejoin but last year's deal still sticks in my throat. The last thing you need when you are having to transfer to a new base to get your command (i.e pay rent and a mortgage!) is to be told you are getting 10% less than the guy parked at the gate next door - it's an insult and you let them get away with it last year.
Unions are about uniting people to fight for common goals and you split the ranks badly last year with this issue - is it any wonder membership isn't where it should be?