Update, 9:40 a.m. EDT: NATS has issued a statement to say that flight restrictions in U.K. airspace will remain in place until 7 a.m. BST tomorrow, at the earliest. We will keep you posted.
(5:30 a.m. EDT) -- British travellers face chaos today as virtually all flights to and from U.K. airports have been cancelled. Britain's Air Traffic Control Service (NATS) earlier today advised the closure of most U.K. airports because of the danger presented by a large plume of volcanic ash headed south and east from an eruption under a glacier in the Eyjafjallajoekull area of Iceland.
From midday today until at least 6 p.m. tonight, there will be no flights permitted in U.K. controlled airspace. All flights from London Heathrow, London Gatwick, Stansted and London City will be cancelled. All Scottish airports are already shut and most regional airports in the U.K. have cancelled or suspended flights, although some have still been operating from southern airports like Bournemouth. Travellers have been advised not to turn up at the airport without checking their flight first. Airlines, including British Airways, easyJet and Ryanair, are offering refunds or the option to rebook.
The precautions have been taken because it is dangerous for aircraft to fly through volcanic ash; there have been cases in the past of engines stalling when they become jammed with particles of rock, sand and glass present in the ash.
The ash cloud, which has reached 55,000 feet, is expected to move through northern Britain later today and cross Europe tonight. Weather forecasters say it should lose intensity as it disperses but the volcano is still erupting so the situation over the next few days remains uncertain.
We'll keep you posted as the situation develops.
--By Sue Bryant, Cruise Critic Contributing Editor