Passengers travelling through London Heathrow on Friday have been warned to expect delays if a 24-hour strike by ground handlers goes ahead.
The planned industrial action will affect operations in terminals one, two and three and is scheduled to start at 0001 on Friday morning.
It is being called by the Unite union, which represents more than 500 ground handling staff who carry out duties including check-in and baggage handling at the airport.
Unite claims that talks between it and ASIG, a subsidiary of LHR's largest ground handler BBA, broke down yesterday "over the delayed 2013 pay award which should have been implemented 14 months ago".
It claims an offer of 5.5 per cent over two years is "unacceptable".
Unite regional officer Michelle Braveboy said: "The prospect of incipient chaos for thousands of passengers should concentrate the minds of management and get them around the table again to negotiate a fair settlement...
"We are still negotiating on the 2013 pay award which should have been paid in July last year and are now having to negotiate a two-year deal as this year's anniversary date has already passed."