Security guards at Heathrow Airport's Terminal Five are set to strike for 10 days from 31 March, which covers school Easter holidays, in a dispute over pay, which could cause chaos for holidaymakers.
Heathrow has said that measures will be taken to ensure the airport remains operational.
British Airways will be the most affected as the Terminal Five exclusively deals with the airline's flights.
Security staff at Heathrow Airport, members of Unite, will stage a 10-day walkout over Easter due to pay concerns.
The walkout – from 31 March to Easter Sunday – will involve more than 1,400 staff and could affect passengers flying into and out of Terminal Five, used solely by British Airways.
Contingency measures will be implemented to keep the airport running, Heathrow said.
Commenting on the walkout, Unite General Secretary Sharon Graham said: "It is the airport's workers who are fundamental to its success and they deserve a fair pay increase."
The strike action comes in reaction to Heathrow's offer of a 10% pay rise, which the union said would not make up for pay freezes and pay cuts that have taken place in recent years.
Throughout the dates of the strikes, workers will be required to work overtime to keep the airport operational.
The strike also follows news that Passport Office workers will strike for the next five weeks as part of a continuing pay and job conditions row.
Unite members previously voted in favour of action, prompting Unite's general secretary to claim that workers at the airport were on poverty wages, while Heathrow CEO and senior managers enjoyed high salaries.
Sources differ in their estimates of just how many staff will strike, with some reporting 1,400, and others suggesting as many as 3,000, and further differences in descriptions of which workers the strike affects, with some sources emphasising the security guards at Terminal Five, others also including cargo inspection, and others adding engineers and firefighters, for example.