Planes finally take to the sky, but for how long?

Some UK airspace is expected to reopen from 1pm, although the main London airports will remain closed for the forseeable future after the Eyjafjallajokull volcano showed signs of intensifying activity.

Flights from Heathrow and Gatwick are “unlikely” today, according to NATS, the air traffic control company.

The news brings fresh uncertainty for more than 150,000 holiday makers and business people stranded abroad and the airlines that are losing millions of pounds every day they are forced to cancel operations.

However, British Airways announced it cancelled all short-haul flights today based on the latest information about the volcanic ash cloud.

The airline said it hoped to run long-haul flights scheduled to depart after 4pm, depending on a “full and permanent” opening of airspace.

It urged passengers to check flight details on before leaving for the airport.

EasyJet said all its flights to and from northern Europe were cancelled until 5pm, but it would continue to operate routes in southern Europe.

The airlines now face a “huge logistical operation” as they prepare to resume service and clear the huge backlog, with planes and crew not in the right places.

And planes might not be back in the air for long as air traffic control company Nats said the conditions were changing rapidly.

People hoping to travel through France by rail to make their way back to the UK were further delayed by a French strike over pay and conditions.

For those still hoping to travel, the lifting of flight restrictions will not necessarily immediately herald good news, according to travel industry representatives.

“Some of those people might have made their own way back to the UK, especially if they have been in Europe, but not everybody has been able to do that.”

“Many businesses are also likely to be hit by the cost of having to cover absences with supply staff,  highlighting the importance to businesses of all sizes in enabling employees to have immediate, secure access to solutions like mobile communication devices that are both readily available, affordable and simple to use – even if they do not have a formal continuity plan in place.” said the Federation of Small Business.