Longer wait times at passport control between December 23 and 31 can be expected due to Border Force strikes, Gatwick has warned.
The industrial action will impact passengers entering the UK, according to the airport.
“UK Border Force strikes will impact passengers entering the UK. Check the status of your flight with your airline before you travel and allow extra time to complete your onward journey,” a Gatwick statement said.
“The UK Border will remain open and we expect flights to operate as usual during this time.”
Passport checks may take longer than usual between December 23-26 and December 28-31.
Other airports due to be affected by the Public and Commercial Service (PCS) dispute are Heathrow, Manchester, Birmingham, Glasgow and Cardiff.
Unconfirmed weekend media reports suggested that passengers could be held on aircraft to prevent overcrowding in airport arrival halls on strike days when more than 10,000 flights are expected to land at the affected airports.
Airlines vowed to maintain their Christmas and New Year schedules after the government announced last week that military personnel, civil servants and volunteers from across government were being trained to support Border Force at airports during the strikes.
Heathrow also projected a week ago that the “vast majority” of travellers will be unaffected by Border Force strikes.
The London hub said: “We are doing everything we can to protect a full flight schedule on strike days, so departing passengers should expect to travel as normal.
“Arriving passengers with UK, EU, US, Canadian and some other passports will be able to use e-gates as usual and their journeys should be largely unaffected on strike days.
“Border Force has contingency measures to ensure other arriving passengers are cleared safely and as quickly as possible. We are continuing to support them to strengthen these plans so that as few people are impacted as possible.
“If passengers who cannot use e-gates are concerned about travelling during the strikes, their airline may be able to offer them alternative travel dates.”
Manchester airport is expecting its busiest December for three years, with more than 1.7 million passengers expected this month.
A statement said: “The festive period is always particularly hectic, with travellers jetting off to spend time with family and friends, and this year many will be looking forward to a first Christmas together since the pandemic restrictions that kept them apart were lifted.”
The northern hub urged passengers to prepare for their journeys and issued a step-by-step guide.
Meanwhile, members of the Unite union at Highlands and Islands Airports Ltd (Hial) have walked out in the first of two strikes taking place this month.
Hial said the action would close Barra, Benbecula and Sumburgh airports and limit operations at Stornoway and Kirkwall.
It expects Campbeltown, Dundee, Inverness, Islay, Tiree and Wick John O’Groats to be open as normal.
The strikes are being staged today (Monday) and on Thursday as part of a pay dispute.