Staff have accused BA of “betrayal” at a protest over the job cuts amid the coronavirus pandemic.
Speaking to the 100-strong crowd at Brighton seafront, chair of the transport select committee Huw Merriman said the “management are rattled”.
A spokesman for BA said: “We are acting to protect as many jobs possible.”
Mr Merriman, the Conservative MP for Bexhill and Battle told protesters: “This is a PR disaster for BA. Management are rattled by the response to this.
“You must keep up the fight because I think this fight is there to be won.”
The protest outside BA’s i360 attraction, attended by staff from cabin crew to engineers, has cross party support which Hove’s Labour MP Peter Kyle said showed how “appalling” BA’s behaviour had been.
“BA have used the coronavirus crisis to wage war on their own staff,” he said.
“This is completely unacceptable.
“Brighton and Hove has huge numbers of people working in aviation… BA right now is attacking the fabric of our community.”
As the employees chanted “BA betrayal”, one worker said it was “cruel and heartbreaking” how BA had acted towards “its loyal and dedicated workforce”.
Unite executive officer Sharon Graham claimed BA’s “fire and rehire” plans would “damage the previously trusted brand”.
BA said it had set up meetings to discuss the situation with Unite and the GMB, but neither union would engage in talks.
The spokesman added: “The airline industry is facing the deepest structural change in its history, as well as facing a severely weakened global economy.
“We call on Unite and GMB to consult with us on our proposals. Working together we can protect more jobs as we prepare for a new future.”