Both Stansted and Luton Airports are warning that flights to Greece could be cancelled or delayed because of a strike by Air Traffic Controllers there.
It started at 9pm last night and is due to end at the same time tonight.
Passengers are being urged to check before they travel.
Police at London Luton Airport are on a high state of alert following the explosions in Belgium.
Airport managers say the threat level was high before today's incidents and that officers are providing high visibility policing around the airport.
Stansted are also increasing security as a precautionary measure.
In response to this morning's events at Brussels Airport, the police presence has been increased in landside areas at @stn_airport 1/3
It is important to note that these are precautionary measures and we continue to closely monitor the situation 2/3
No airlines at Stansted offer direct flights to Brussels. All other flights are currently operating as normal 3/3
Drivers are being warned to leave more time for their journey to Luton Airport while resurfacing works are carried out.
The works, on a key link road to London Luton Airport, are due to take place during the evenings from 7pm-4am from Monday 22 to Thursday 25 February.
Frank Lester Way will be closed to motorists, whilst the remaining junctions of the roundabout will be controlled using temporary traffic lights.
A diversion will be in operation via Eaton Green Road, Vauxhall Way and Airport Way.
The works are likely to cause some congestion and motorists are advised to allow extra time when planning their journeys to and from the airport.
“Resurfacing is essential to ensure that Luton’s roads are kept in good condition for drivers and these works follow concerns raised locally about the road surface. Whilst every effort is being made to minimise the impact on the road network, there was never an ideal time to carry out these works given the road serves the airport 24 hours a day, seven days a week. We apologise in advance for the disruption.”
Luton Airport has had it's busiest ever year - with 12 million passengers passing through in 2015.
That's a 16% increase year on year - and represents the biggest growth in numbers of all airports in the region.
The airport is currently undergoing a £110 million redevelopment. When complete in 2020, the capacity at the airport will increase by 50%- from 12 million to 18 million passengers.
The transformation will deliver major upgrades to the airport's facilities, including:
- A complete redesign of the terminal to create a quick, friendly and convenient passenger experience.
- Doubling of the existing retail space, introducing exciting shopping and dining options, including a new executive lounge.
- A new multi-storey car park with more than 1,5000 spaces.
- The addition of Oyster card services through to the terminal building.
Peterborough-based travel company Thomas Cook has cancelled all flights and holidays to Sharm el Sheikh until November 25.
Customers due to travel up to Thursday December 10 will be offered the chance to re-book their trips or cancel them.
Meanwhile two Thomas Cook flights will depart Sharm el Sheikh this evening, bringing holidaymakers back to the UK.
A British aircraft carrying 189 passengers from Stansted Airport had a near-miss with a military missile when landing at Sharm el-Sheikh airport just over two months ago, it has emerged.
The incident has come to light as British tourists in the Egyptian resort begin to return home following the grounding of flights amid security fears.
Reports of the incident say the Thomson aircraft had to take evasive action but landed safely. Thomson reported the incident to the Department for Transport.
A UK government spokesperson told ITV News: "We investigated the reported incident at the time and concluded that it was not a targeted attack and was likely to be connected to routine exercises being conducted by the Egyptian military in the area at the time."
An easyJet flight carrying 179 passengers from Sharm el-Sheikh in Egypt has safely arrived back at Luton Airport.
easyJet had hoped to fly out hundreds more tourists on nine flights, but in the end the Egyptian authorities only allowed two to depart.
The other has gone to Gatwick. EasyJet hope to lay on more flights tomorrow.
Click below to see the flight land
easyJet have confirmed that their flight from Sharm el-Sheikh to Luton Airport has just taken off.
@easyjet are pleased to confirm that EZY9398 to London Luton has departed from Sharm El Sheikh with 179 passengers on board
The EZY9398 flight is due to arrive back in Bedfordshire at around 16:00.
There are 179 passengers on board.
Crowds of British tourists continue to be stranded at Sharm el-Sheikh airport as they await news following reports that Egyptian authorities have suspended UK rescue flights entering the airport.
One easyJet fight will be allowed to return to Luton Airport today from Sharm el-Sheikh, but the rest will be cancelled.
Another flight to Gatwick will also still go ahead.
Egyptian authorities have suspended "rescue flights" back to the UK according to the budget airline.
It was hoped that easyJet and other airlines would be able to resume some of its flights from Sharm el-Sheikh today but those plans have been scuppered.
Which flight has been allowed back?
- EZY9398 Sharm el-Sheikh to London Luton
Which flights have been cancelled?
- EZY9555 Sharm el-Sheikh to London Luton
- EZY9333 Sharm el-Sheikh to London Luton
- EZY9666 Sharm el-Sheikh to London Stansted
- EZY2398 Sharm el-Sheikh to London Luton
“Whilst this is outside of our control we would like to apologise to customers for the delay.
All customers will be provided with hotel accommodation and we are keeping them informed. We would advise passengers also to check Flight Tracker for updates.”