British Airways workers based at London's Heathrow AIrport have voted to strike in a dispute over pay.
Members of the GMB and Unite backed industrial action.
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."
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."
A British government spokesperson said a strike by British Airways workers would add to the "misery" passengers are suffering at airports.
"This is obviously a matter for British Airways and the unions and we would strongly encourage both to come together to find a settlement," a Downing Street spokesperson said.
"We don't want to see any further disruption for passengers and strike action would only add to the misery being faced by passengers at airports."
Recent data from the Central Statistics Office showed that London-Heathrow was the most popular route at Dublin Airport, and the second most popular at both Cork Airport and Shannon Airport.