He means he'd rather reach agreement with you and be friends than have a fight with you, but, if it does come to a fight, there will be only one winner.
Employment law? Irrelevant until the shape of the takeover (IF there is one) is known.
If the cost of reaching agreement is higher than the benefits of the takeover, he will just sit back until BA have handed you all your P45s, and then accept your applications for employment. Employment law and TUPE are then equally irrelevant, as neither will apply.
Now, perhaps you could explain to us all exactly where the strength of your "bargaining position" lies?