Hundreds of workers at Heathrow will walk out in the run-up to the World Cup finals this month over demands for better pay.
Unite said 700 staff, who are involved in ground-handling, airside transport and cargo and are employed by Dnata and Menzies at Heathrow, will strike for three days starting from 18 November.
“It will lead to disruption, cancellations and delays at Heathrow terminals 2, 3 and 4”, the union said in its statement.
“The strike action will particularly affect Qatar Airways, which has scheduled an additional 10 flights a week during the World Cup”.
It added that other airlines to be “hit heavily” would include Virgin Atlantic, Singapore Airlines, Cathay-Pacific and Emirates.
Passengers returning to the United States for the Thanksgiving holiday, which falls on 24 November, were also likely to be among those affected.
Unite said both companies, which are contractors to airlines, had offered pay cuts when compared to the rate of inflation.
Dnata had offered its workers a 5% increase, the union said, while the offers for Menzies workers varied between 2% and 6%.
They, Heathrow and the airlines were yet to comment.
Unite regional officer Kevin Hall said: “Strike action will inevitably cause disruption, delays and cancellations to flights throughout Heathrow, with travellers to the World Cup particularly affected.
“However, this dispute is entirely of Dnata and Menzies own making. They have had every opportunity to make a fair pay offer but have chosen not to do so.”