Airlines and passengers, including those affected at Leeds-Bradford International Airport, are braced for a slow return to normality as British airspace reopened.

A "phased" resumption of flights to and from the UK is underway as operators set about working on contingency plans to get back to business while complying with conditions imposed by the Civil Aviation Authority (CAA).

Airlines rushed to reschedule flights but there were warnings it could be weeks before services returned to normal. The CAA stepped in to ease restrictions on Tuesday night and described the chaos as a "a situation without precedent".

It is estimated hundreds of thousands of passengers were left stranded abroad in a shutdown thought to have cost the industry about £130 million a day.

Low cost airline Jet2.com, based at Leeds-Bradford International Airport, has more than 50 flights to and from Europe which are ready for booking immediately on the its website today As part of an ongoing effort to bring customers home, the airline has flights to accommodate passengers as quickly as possible to and from Alicante, Murcia, Palma, Nice, Faro, Malaga and Sharm el Sheikh.

In addition, hundreds of passengers have already started arriving home via coaches that have been provided by the airline.

Ian Doubtfire, managing director at Jet2.com, said: "We urge passengers to go onto the Jet2.com website and start booking their flights as soon as possible.

He said: "Our priority is to bring people home as quickly and safely as possible. The team here at Jet2.com are working around the clock to ensure that our valued passengers receive the excellent service they have come to expect from the North's favourite airline."

An easyJet spokesman said it would take "several days" to get services back to normal. "Following the re-opening of airspace across the UK and Europe, easyJet plans to resume some services across the UK and Continental Europe today," he said.

"Due to the extent of the disruption, it will take several days to resume normal operations and delays are likely. Passengers booked on an easyJet flight should go to www.easyJet.com before travelling to the airport to find the latest status of their flight."

Operator bmi said yesterday it would resume services today with some flights from 9.15am, while East Midlands Airport said it would resume operations but added commercial flights would be "dependent on the decisions made by airlines and tour operators".

Meanwhile, Transport Secretary Lord Adonis said the Government was not forced to reopen UK skies by "pressure" from airlines.

He said "continuous assessments" had been made throughout the shutdown caused by the volcanic ash cloud.

He said: "At every stage decisions were based on the decisions of safety regulators. They have not been based on pressure from airlines, and that is what the public would expect."

He was speaking after British Airways boss Willie Walsh said "lessons can be learned" from the handling of the event.

Mr Walsh said: "I don't believe it was necessary to impose a blanket ban on all UK airspace last Thursday.

"My personal belief is that we could have safely continued operating for a period of time."

Passengers began landing at airports around the UK on Tuesday night, with the first BA flight since the restrictions were eased touching down at Heathrow just before 10pm.

Despite the initial arrivals, more flights are not expected to land until Tuesday afternoon as the airlines attempt to clear the backlog.

A BA spokeswoman said: "We are expecting to see our long-haul flights going out from Heathrow this morning but we don't expect our first inbound flight to land until around 1pm this afternoon."

A statement on the British Airways' website said it would take time to return to a "full flying programme" because many aircraft and crew were out of position.