Workers at Heathrow airport are to vote on whether to strike in a dispute over pay.
Unite said over 3,000 of its members working as security guards, engineers and firefighters will begin balloting for strike action on February 17.
The ballot will close a month later.
Unite general secretary Sharon Graham said: “Heathrow Airport is guilty of gross hypocrisy, it is paying telephone number salaries to its chief executive and senior managers, but the workers who make the company a success are on poverty wages.
“Unite never takes a backward step when fighting for its members’, jobs, pay and conditions and our members at Heathrow Airport will receive the union’s complete support.”
A Heathrow spokesperson said: “We are extremely disappointed that Unite is tabling a formal ballot for industrial action.
“This step unnecessarily escalates matters and if strikes do go ahead the pay offer will be withdrawn.
“Since last November, discussions with our unions have resulted in an offer of a 10% increase on salary, shift pay and allowances this year on top of a 4% increase six months ago – this is despite Heathrow remaining loss-making and with significant uncertainties facing our business, including the spectre of Covid travel restrictions which we have already seen re-introduced just this year.”