Passengers have been warned that they face disruptions to flights at Heathrow as workers prepare to go on strike.
Ground handlers employed by a private contractor at the West London airport are set to walk out amid a row over pay.
About 350 members of the trade union Unite working for Menzies plan to walk out for 72 hours from 4am on Friday, December 16.
The action will lead to some flight disruptions, the union said.
Heathrow has been dogged by problems since the Covid pandemic struck, resulting in huge queues, lost baggage and cancelled flights. Last month, the airport was told by Willie Walsh, director general of the International Air Transport Association (Iata) to get its act together and address a litany of problems.
Trade union general secretary Sharon Graham called on employer Menzies "to have a long, hard look at itself".
“This is a highly lucrative company, which has made a fair pay offer to one group of its workers but isn’t prepared to make a similar offer to its ground handlers," she said.
“Unite is entirely dedicated to defending its members’ jobs, pay and conditions.
“Our members at Menzies will continue to receive the union’s complete support.”
Unite said the ground handlers were offered a flat rate increase — which the union branded a real-terms pay cut.
Heathrow last month won back its crown as Europe’s busiest airport after attracting 5.8 million passengers between July and September. The figure was more than that recorded by airports in rival cities such as Paris, Amsterdam and Frankfurt.
A Heathrow spokesman said: “We are aware of industrial action proposed by Menzies colleagues from December 16-18 .
“We encourage airport partners who would be affected to continue with their contingency planning and we will support them to minimise the impact on passengers, should the strike go ahead.”
Menzies workers walked out in November but caused little disruption.