Unite Union is planning on staging a series of walkouts among employees at the Heathrow Airport.
The walkout is related to an ongoing row over pay and conditions.
The first strike will take place today (December 1) and involves firefighters, engineers, security, baggage personnel, central terminal operations, landside and airside workers.
More action is planned for December 14, 17 and 18 if the issue is not resolved.
Unite Officer Wayne King said: “Heathrow workers take great pride in their work and have continued to operate throughout the pandemic, and have been required to put their own health at risk attending to passengers who have developed Covid.
“They are taking strike action as a last resort as cuts to their pay of up to a quarter are forcing them into poverty.
“Unite has offered a variety of solutions to reduce costs and avoid industrial action, all of which have been summarily dismissed by HAL.”
A spokesperson for Heathrow Airport said: “It’s very disappointing that Unite has decided to take strike action during the worst crisis to hit the aviation sector.
“Our focus has been to protect jobs, which is why we’ve offered every frontline colleague who wants one a job at a market rate salary above the London Living Wage, even despite a loss of over £1.5bn to our business so far this year.
“We do not believe this strike action is necessary, but have activated extensive contingency plans which will keep the airport open and operating safely throughout this period.”