AIRPORTS around Britain have suffered major flight disruption after the return of the Icelandic ash cloud caused chaos for thousands of passengers.

A no-fly order saw Heathrow and Gatwick closed until 7am today (May 17), with both only partially due to reopen over the next six hours, air traffic authority NATS said.

Flights have also been grounded until lunchtime across Northern Ireland and much of Scotland and Wales, with warnings of widespread knock-on disruption later in the day both in the UK and abroad.

No arrivals are expected at Gatwick until 1pm at the earliest, while Heathrow will see reduced take-offs and departures as well as extended delays and cancellations.

Some big regional airports like Manchester, Glasgow and London Stansted are open, but passengers everywhere have been urged to check with their airlines before leaving for the airport.

NATS warned the ash cloud was "continuing to change shape" as it spread over southern England to Northern Ireland and as far north as the Shetland Isles.

The latest air travel chaos comes a month after the Eyjafjallajokull volcano eruption cancelled a swathe of flights across Europe, and as talks continue to avert a crippling five-day strike by British Airways cabin crew.

There are warnings that the ash restrictions could persist in the UK until tomorrow.

Forecasters are expecting a change in the north-westerly wind direction, which is expected to blow the "high density" cloud from the volcano away from Britain on Tuesday.

Are you flying soon and worried your flight could be cancelled? Have your say below.