This looks pretty much like a pre-emptive
PR strike to me.
BASSA/Unite are 'throwing an olive branch' to the company for them to peruse and accept reject as they see fit.
Once rejected then Unite have to call the strike but assault the press with slogans based upon the rhetoric such as 'We offered them the savings but they didn't take them' and 'We were prepared to take cuts but BA want the whole cake' etc... etc... etc...
Sadly this blatent attempt at gaining the public sympathy vote doesn't take into account that BA has never asked for pay cuts. BA has never threatened actual, enforced, permanent job losses. BA has asked for a minor productivity increase which has enabled 1000 VOLUNTARY redundancies and thousands to take up part time work. A rather generous lifestyle choice on the part of the participants.
BASSA have had a year to engage in meaningful discussion and have failed. Time up. Call the strike and take the consequences.