A planned strike by Heathrow Airport workers on Monday has been suspended to allow further talks on resolving a pay dispute.
Members of the Unite union were due to walk out from one minute past midnight for 48 hours.
The two sides have been meeting throughout the weekend under the chairmanship of the conciliation service Acas.
Unite said in a brief statement: “Tomorrow’s strike by Unite members working for Heathrow Airport has been suspended to allow for further talks at Acas tomorrow.
“Under the chairmanship of the conciliation service Acas, tomorrow’s talks will involve senior directors from Heathrow Airport and senior Unite officials with the aim of averting a second day of planned strike action set to start at 00:01 and finish at 23:59 on Tuesday 6 August.
“Unite will not be making any further comment while talks are ongoing.”
Heathrow has already cancelled around 177 flights on Monday and Tuesday, causing disruption to passengers.
But the scale of disruption would have been worse if Monday’s strike had gone ahead.
Passengers are being urged to check with their airline for the latest news on flights.
Unite members, including security staff, firefighters and engineers have voted heavily against a pay offer Heathrow said was worth 7.3% over two-and-a-half years.
A Heathrow spokesman said: “We will continue talks with Unite tomorrow and we remain hopeful that we can find a resolution and stop this disruptive and unnecessary threat of strike action.
“We regret that passengers have been inconvenienced by this and urge them to contact their airline for up to date information on the status of their service.
“While the vast majority of flights will be unaffected, some airlines are making arrangements to operate flights from other UK airports, others will be delaying flights and unfortunately a number will be cancelled”.
The spokesman added that airlines have now started to contact passengers on affected flights and passengers should contact their airline for more information.
“We recommend passengers check their flight status before travelling to the airport and read the guidance on http://heathrow.com/ to prepare for their journey,” he said.