Litebulbs, the financial position of BA is stronger due to the cost savings implemented by all other parts of BA, including the imposition of crew reductions. If BASSA are allowed to renegotiate the deal, so will all the other departments, we are back at square one, plus in the cities eyes, no prospects of the structural change required for BA's future to be assured.
That is why BASSA cannot win, or even be seen to have won.