Thousands of airline passengers have had their flights cancelled as dense fog caused disruption at airports in the south east of England.
A total of 21 flights had been cancelled at Heathrow by 6.30am, with 10 departures called off at London City Airport.
Forecasters have warned that the weather conditions could persist until late morning, with the risk of further delays for passengers.
A spokeswoman for the airport said: "Passengers are being re-booked or put up in accommodation by airlines, while some domestic passengers are being taken in coaches to their destination.
"Some delays to flights are also occurring so we advise passengers to check with their airlines before travelling."
The destinations affected by cancellations at Heathrow include Manchester, Glasgow, Amsterdam, Brussels, Stockholm, Cologne and Nice.
Services to Dublin, Rotterdam and Paris are among those hit at London City.
One flight scheduled to depart from Leeds Bradford Airport to Amsterdam, which has also been affected by fog, was also cancelled.
A Met Office spokesman said: "Fog will take a while to shift in London, the south east and the east of England up to York, and will only become less widespread in the late morning."
More than 100 flights were cancelled on Sunday due to the fog.
Heathrow has said it is aware that 63 inbound and 78 outbound flights have been called off.
Please see below our guidance regarding the Travel Delay/Abandonment and Missed Departure sections of the policy further to the disruptions at the London Airports.
- Travel Delay/ Abandonment: You are covered for Travel Delay Benefit or subsequent Abandonment, as a result of the Adverse Weather; and
- Missed Departure is only covered if on public transport and this is delayed, making you too late to catch your flight and covering for additional costs incurred in reaching destination up to the policy limit. Please advise clients to seek advice and compensation from their carrier.
The cut off date is today Monday 21st November 2011 at 09:00 GMT therefore policyholders whose policy was purchased after this date will not be covered under the policy.
We would be very grateful if you could please distribute this information to all staff members.