Heathrow airport is calling for talks at the conciliation service in a bid to avert a planned series of strikes next month.
About 1,400 security guards in the Unite union are set to stage eight strikes in a dispute over pay, including during the coronation of King Charles, following walkouts over Easter.
A Heathrow spokesperson said: “We kept Heathrow running smoothly during the first 10 days of Unite’s failed industrial action, and passengers can have confidence that we will do so again this time.
“We will not let Unite disrupt the flow of visitors to the UK during such an important period for the country.
“The majority of Heathrow colleagues do not want to strike. Despite regular talks on our improved offer, Unite continues to refuse to let its members have a say on the deal on the table.
“Colleagues could have an inflation-matching pay increase for two years – 10% this year and a CPI linked increase in 2024, as well as a £1,150 lump sum but, instead, they’re left empty-handed by Unite’s actions.
“We have therefore asked for the independent and specialist support of Acas to chair further talks with unions and find a resolution.”