Hundreds of workers will walk out of their jobs at Heathrow Airport ahead of Christmas in a row over pay.
Ground handlers employed by a private contractor at the London travel hub will walk out for 72 hours from 4am on Friday December 16.
Around 350 members of Unite working for Menzies will be involved in the action, the union has said.
The action will lead to some flight disruption, according to Unite, as the busy Christmas period begins to speed up.
General secretary Sharon Graham said: "Menzies needs 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.
"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 have been offered a flat rate increase - which it branded a real-terms pay cut.
A Heathrow spokesperson said: "We are aware of industrial action proposed by Menzies colleagues from 16-18 December.
"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."
It is not currently clear how widespread the disruption will be.
The industrial action follows a 72 hour walk-out by workers with the same company in November.
Then the union warned that the action could impact passengers travelling with airlines including Aer Lingus, American Airlines, Finnair, Qantas and Lufthansa.
Other airlines such as Air Canada, Swiss Air, Air Portugal, Austrian airlines and Egypt Air are also expected to be affected.
A Heathrow spokesperson said the vast majority of passengers will be unaffected later this month, and that the biggest UK carriers would not be caught up in the chaos.
They noted that there were no flight cancellations the last time Menzies workers walked out, but that there were some minor delays.
The travel sector in the UK has been impacted by walkouts in recent months.
Rail, Maritime and Transport Workers union has led a series of strikes since June over pay and conditions on the rail network.
This week the same union said that security staff working on Eurostar will walk out on 16, 18, 22 and 23 December in a dispute over pay.
Miguel Gomez Sjunnesson, EVP Europe, Menzies Aviation said: “We are well prepared for further industrial action and are working closely with key partners to put in place robust contingency plans.
"The previous strike, which involved about 250 of our 1,500 ground handling workforce at Heathrow, had minimal impact on our operations with no flight cancellations attributable to Menzies and 97% of flights departing on time.
"We remain committed to seeking a resolution on the pay talks in our ground handling operations so our employees can receive their increase now, and hope to be able to reach an agreement which is workable for both the business and our employees during our meeting with unions on Tuesday.”
