Latest: Hope for transatlantic flights as volcanic ash falls on Sheffield

The cloud has prevented nearly all flights from entering or leaving the UK since noon on Thursday - wrecking travel plans and leaving thousands stranded.

This afternoon, air traffic control company Nats said flights in and out of England and Wales would remain grounded until at least 7am tomorrow.

But the company added it was lifting, from 7pm today, flight restrictions in a large part of Scottish airspace, including at Scottish airports, the Shetlands and Orkneys, and in Northern Ireland.

Nats said this meant that some North Atlantic services could operate to and from these points.

British Airways, which does not operate transatlantic flights from Scotland but does fly domestic services from Glasgow, Edinburgh and Aberdeen, said it would look at the possibility of using Scotland for North Atlantic services.

Nats said it would make a further announcement at around 8.30pm tonight about flights tomorrow.

The company said it hoped to soon be able to allow individual flights to operate on the same basis as the special permission given to Manchester airport to handle three long-haul flights today - two incoming and one outgoing.

Nats said it hoped there might be some flights from the north into Newcastle after 1am tomorrow.

"In general, the situation is dynamic and subject to change," the company added.

Earlier today, some flights were able to run in the Republic of Ireland and in Scotland, although Transport Secretary Lord Adonis warned it was "likely that significant disruption to most UK air services will continue for at least the next 48 hours".

One of those caught up in the travel chaos was the Duchess of Cornwall.

She had to cancel a visit to a Polish cultural centre in London, where she was to sign a book of condolence for the late president of Poland, Lech Kaczynski, because she was unable to fly from Scotland.

But one airport that was able to operate today was Newquay in Cornwall, where flights to and from St Mary's Airport on the Isles of Scilly were running. These flights operate outside controlled air space so are not subject to the Nats restriction.

Prime Minister Gordon Brown apologised to travellers, saying he was sorry there had been so much inconvenience.

English airports were mostly deserted but small knots of passengers unaware of the blanket ban turned up to find empty check-in desks and no flights.

For the second day running, travellers unable to fly looked for alternative modes of transport.

Channel Tunnel high-speed train company Eurostar reported that its 58 services were full today.

This meant the company was able to handle more than 46,000 passengers on its trains running between London and Paris and Brussels.

Many people took to ferries to reach the Continent. P&O Ferries, whose routes include Dover-Calais, said it was unable to accept any further foot-passenger bookings before Monday "as a result of the unprecedented surge in demand due to the airline crisis".

Coach company Eurolines increased its services to Europe, while some hotels, including Warner Leisure Hotels, cut the cost of weekend breaks.

Holiday park operator Park Resorts said it had seen a 45% rise in inquiries since the air crisis began, while Network Rail said it has cancelled some planned weekend engineering work so that more trains could run.

Dr Ashley Steel, global chairman for transport and infrastructure at professional services company KPMG, said: "This is yet another dramatic and costly event for the global aviation industry which will have a significant impact on annual revenues of airlines in the UK and Europe.

"It will also affect airlines in the US and Asia because, in places around the world, airplanes bound for the UK and Europe have been grounded."

Minicab company Addison Lee said it had received requests for journeys to cities as far away as Paris, Milan, Amsterdam and Zurich.

One booking, by a businessman, was to Salzburg in Austria.

Concierge and lifestyle management company WhiteConcierge said it had seen a huge increase in bookings for rail and ferry services.

Scientists from Sheffield Hallam University said they had collected samples of the ash and confirmed it was volcanic.

Dr Hywel Jones, consultancy manager from the university's Materials and Engineering Research Institute, spotted the dust on his cycle ride into work.

Samples were collected from cars parked in Sheffield Hallam's Science Park.

Dr Jones said: "We analysed the samples and found they contained silicon and oxygen, calcium, aluminium and sodium, which make up volcanic matter."

A spokesman for Leeds Bradford International Airport said: "We're asking all passengers affected to contact their airlines to get the latest information and to use our website for all the latest information on arrivals and departures."

A spokeswoman for Humberside Airport said eight flights had been cancelled on Thursday morning as a result of the ash, and added that the situation would be reviewed.

A statement from Robin Hood Airport Doncaster Sheffield said: "A volcanic eruption in Iceland is pumping clouds of ash into the atmosphere. This is being blown towards UK airspace and will cause significant disruption for flights departing from and arriving to Robin Hood Airport Doncaster Sheffield on Thursday."

The ash, from the Icelandic mountain Eyjaffjalljokull, also caused airport and aircraft movement shutdowns in other parts of Europe, including France, Sweden, Finland, Denmark and Holland.

Einar Kjartansson, a geophysicist at the Icelandic Meteorological Office, said: "It is likely that the production of ash will continue at a comparable level for some days or weeks. But where it disrupts travel, that depends on the weather. It depends how the wind carries the ash."

Passengers, meanwhile, put their dream holidays on hold for a second day.

Barbara and Tony Mallinder had left their home in Rotherham at 1am, understanding their flight to Shanghai would leave later this afternoon.

They are due to leave on a cruise around Hong Kong, Vietnam and Japan on Sunday, but now fear they won't make it.

Mr Mallinder said: "If we don't get there, it's not going to wait for us. We'd be stuck in no man's land."

His wife added: "We didn't know it would still be shut. Unlike other people, we can't go 48 hours later and have the rest of our holiday.

"But it can't be helped. They can't send the planes up if it's dangerous."

Student Hannah Miller, 21, from Sheffield, was meant to be flying to Brisbane, Australia, to see friends she met while travelling last year.

She said: "We came down this morning as we'd been booked in a hotel overnight. But now we're here, and we've got nowhere to go.

"Last night was stressful, but now we've just had to wake up and get on with it."

Her friend Jessica White, 23, said: "I'm just fed up. We've got nowhere to go and nothing to do, and no-one's telling us anything.

"We got told to go home, but we can't do that as it's such a long way away, and we want to be here when the flight comes up."