Members of the Unite union at Heathrow are due to take part in the first of four planned strikes on Tuesday.
The union has planned the strikes following a dispute over wage cuts and what it describes as Heathrow’s “brutal fire and rehire programme”.
A further one-day strike is planned for December 14, followed by a two-day stoppage on December 17 and 18.
Unite’s members include firefighters, engineers, campus security and those working in baggage operations, central terminal operations, landside and airside operations.
Unite regional co-ordinating officer Wayne King said: “If this was genuinely about the pandemic any cuts would have been temporary. Unite have tried to negotiate temporary pay cuts but Heathrow were simply not interested.
“HAL has claimed that under its ‘contingency plans’ Heathrow can operate safely but despite seeking the evidence to prove this, that information has not been forthcoming, raising serious questions about how the airport will operate during the strikes.”
A Heathrow spokesman 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.”
City AM reported that less than 3% of Heathrow workers will have their pay reduced by more than 20% and less than 1% of staff will have their pay reduced by a quarter under the proposals.
It said that 4,263 of 4,642 frontline staff (92%) have so far accepted the proposals.