Ground staff employed by a private contractor at Heathrow Airport will begin a 72-hour strike on Friday.
Around 350 members of Unite working for Menzies will walk out from 4am.
Unite general secretary Sharon Graham said: “Unite’s members at Menzies play a critical role in ensuring that planes operate safely at Heathrow.
“Menzies is a wealthy company and it can fully afford to pay its workers a decent pay increase.
“Unite’s members at Menzies will receive the union’s comprehensive support.”
Unite said Menzies had made pay offers below Retail Price Index (RPI) inflation.
Unite regional officer Kevin Hall said: “The strike action will inevitably cause serious delays for passengers at Heathrow but this dispute is entirely of Menzies’ own making.
“It has had every opportunity to make our members a fair pay offer, but it has stubbornly refused to do so.”
Strikes scheduled to take place involving workers at Dnata have been called off after members accepted an improved offer.
Strike action involving Menzies workers employed in its cargo and trucking sections has been suspended to allow the workers to be balloted on an improved offer, which means passengers with Qatar Airways going to the World Cup will not be directly affected by the dispute, said Unite.
Alex Doisneau, managing director, Dnata UK, Airport Operations (Ground Handling & Cargo), said: “We are pleased to have reached agreement on this pay award, which reflects the huge respect we have for our employees in the UK.
“The agreed package, including both a pay increase and immediate support for the short term, provides concrete support for our employees amidst the current cost-of-living crisis.
“Dnata is heavily invested in the UK and we look forward to continuing our journey with our employees as we focus our efforts on strengthening our leading position in the market.”
A Heathrow spokesperson said: “A number of Menzies colleagues will go on strike at Heathrow this weekend.
“Affected airlines already have contingency matters in place and flight cancellations are not anticipated.
“We encourage passengers to check the status of their flight with their airline.”
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