read what hand solo said again.
BA do not HAVE to merge the lists. BMI can operate as a standalone fleet, with TUPE allowances and not a penny more.
The previous BA / BACC ballot had 2 very strong red lines. BA said "NO COST INCREASE FROM BMI CURRENT COST" - that means you ain't gonna get teh BA paypoint or senioroity. thats a clear position from BA and IAG, not from the BACC.
BACC said "no ba pilot to be disadvantaged", thats a bit more nebulous, but fairly clear too - and the 10 million savings get thrown back off the table if thats not met.
I have no idea about employment law, and neither do 99.99999% of people on here. I would imagine that if you forced a merger of the lists, you would probably have to do it in an equitable manner - but thats not gonna happen. My view is that either BMI DECIDE to join that list at a negotiated and agreed position, or they don't join it at all, there is going to be nothing forced about it. Thats a completely diffreent kettle of fish from previous positions.