The UK’s first flight following the airport shutdown took to the air today but the threat of a new volcanic ash cloud from Iceland was hampering efforts to get more services off the ground.

Air traffic control company Nats said eastern Scotland and an area of northern England would be allowed to operate flights before 7pm.

With Scottish airspace reopening this morning, the first flight took off from Glasgow airport bound for Stornoway, on the Isle of Lewis, at 7.15am.

But only a handful of Scottish-destination flights were listed on the departure board.

Airports and airlines that had hoped to start operations again were having to postpone their plans as air traffic control company Nats warned that another ash cloud was spreading south and east towards the UK.

An estimated 150,000 Britons have been stuck overseas as a result of the airports shutdown, with the Royal Navy being involved in the repatriation exercise and holiday companies laying on coaches to bring those stranded in Europe home.

Foreign Secretary David Miliband today advised those stuck in Europe to head for Calais.

He said: “This is an unprecedented situation, it is affecting the whole of northern Europe, so our priority is first, to make the most of the hole in the clouds that is going to emerge because of the temporary stalling yesterday of the volcano, secondly, to continue to offer as much consular assistance as we can to Brits who are stranded around the world.

He added: “I think the first message to British people who are in Europe though is to go to Calais because it is from Calais that they can cross the Channel.”

Prime Minister Gordon Brown said airports were “taking advantage of the window of opportunity” but he insisted passenger safety would remain “paramount”.

His comments came as the first of three Royal Navy warships began rescuing Britons stranded by the air chaos today.

HMS Albion came alongside at Santander in northern Spain this morning and started loading about 250 troops and 200 civilians to take them back to the UK, the Ministry of Defence said.

Another two Navy vessels, aircraft carrier HMS Ark Royal and commando helicopter carrier HMS Ocean, have also been deployed to rescue stranded British travellers from the Continent.