British Airways workers based at Heathrow have voted in favour of strikes in a dispute over pay, the GMB and Unite have unions announced.
The unions said holidaymakers face disruption, warning of a summer of strikes.
Workers, including check-in staff, will now decide on strike dates, which the union said were likely to be held during the peak summer holiday period.
Nadine Houghton, GMB national officer, said: “With grim predictability, holidaymakers face massive disruption thanks to the pig-headedness of British Airways.
“BA have tried to offer our members crumbs from the table in the form of a 10% one-off bonus payment, but this doesn’t cut the mustard.
“Our members need to be reinstated the 10% they had stolen from them last year with full back pay and the 10% bonus which other colleagues have been paid.
“GMB members at Heathrow have suffered untold abuse as they deal with the travel chaos caused by staff shortages and IT failures.
“At the same time, they’ve had their pay slashed during BA’s callous fire and rehire policy.
“What did BA think was going to happen?
“It’s not too late to save the summer holidays – other BA workers have had their pay cuts reversed.
“Do the same for ground and check-in staff and this industrial action can be nipped in the bud.”
Unite officer Russ Ball said: “The problems British Airways is facing are entirely of its own making. It brutally cut jobs and pay during the pandemic even though the Government was paying them to save jobs.
“In the case of this dispute, they have insulted this workforce, slashing pay by 10% only to restore it to managers but not to our members.
“BA is treating its loyal workforce as second class citizens and they will not put up with it a moment longer.
“Strike action will inevitably cause severe disruption to BA’s services at Heathrow.
“The company has a short window of opportunity to reinstate our members’ pay before strikes are called. I urge BA not to squander that opportunity.”
Members of the GMB voted by 91% in favour of industrial action while Unite said 94% of its members backed action.