The UAE's two biggest airlines on Monday announced they were cancelling a total of five flights to the UK later this week in response to strike action plans by UK border agency staff.
Emirates and Etihad said the cancellations would spare travellers anticipated disruption at Heathrow Airport, and the long delays for those waiting to clear immigration.
A statement issued by Emirates said EK029 and EK030 - Dubai to London Heathrow and the return flight - would be grounded on Wednesday "due to the announced strike of the UK Border Control Authority at all UK airports".
The airline said there was likely to be "significant disruption and extensive delays for arriving and departing passengers in and out of the UK".
The statement added: "Passengers are strongly encouraged to consider alternate travel days."
The decision by Emirates is in line with that of Abu Dhabi carrier Etihad which has cancelled three flights on Wednesday.
The cancelled flights are EY019 from Abu Dhabi to London Heathrow, EY020 from London Heathrow to Abu Dhabi and EY017 from Abu Dhabi to London Heathrow.
Flight EY011 from Abu Dhabi to London Heathrow will also operate with reduced passenger capacity.
Etihad officials said guests booked on these flights would be rebooked on alternative journeys.
Flights to Manchester would continue operate as scheduled, the airline said.
Etihad is among several Gulf carriers which have urged passengers travelling to London and other UK airports this week to switch their travel plans in a bid to avoid delays.
A 24-hour strike by up to 18,000 passport and immigration staff is expected on Wednesday in protest of changes made to their pension plans.
Thousands of immigration officials are expected to join union staff representing teachers, health workers and civil servants, in the biggest union protest since the “Winter of Discontent” in 1979.
Unions are opposing moves to make government employees retire later and contribute more towards their pensions.
Qatar Airways has urged passengers travelling on Nov 30 to contact its reservation office or local travel agent for rebooking options.
“The airline is offering rebooking options for passengers holding confirmed reservations for travel on November 30 on any of the affected flights arriving into London Heathrow or Manchester,” said a statement on its website.
Heathrow, Europe’s busiest airport, is expecting delays of up to 12 hours, Normand Boivin, COO of the UK hub said in a letter posted on the airport’s website.
Carriers flying into the airport have also been asked to reduce passenger loads.
“We will plan for normal flight schedule but are requesting all carriers to reduce load factors on each international flight arriving into Heathrow on Nov 30 to 50 percent of normal levels,” said Boivin.
* Additional reporting by Andy Sambidge