Britons have returned from crisis-hit Libya on a BP-chartered flight that landed at London's Gatwick Airport carrying 150 people.
A Gatwick Airport spokesman said passengers would be offered counselling as they came off the flight. The arrival comes hours after it was announced that an RAF Hercules military transport aircraft had landed in Tripoli.
The C130 is one of two placed on standby to boost capacity being provided by a number of charter planes, a Government official travelling with Prime Minister David Cameron in the Gulf said.
It follows criticism of the speed of the Government's response to the crisis. Last night, the prime minister made a further call to Foreign Secretary William Hague and Defence Secretary Liam Fox to be briefed on the latest developments.
There was "no higher priority" for the premier than getting the around 550 Britons out of the country, an official said.
He added permission was still being sought for HMS Cumberland to dock at second city Benghazi, where there are around 100 people trying to get back to the UK.
There are another 150 or so in the Libyan desert who were widely dispersed but starting to gather together. The Government was "considering a number of options" as to how they could be rescued, he said, but would give no details.
The repatriation effort comes amid ongoing violence on the ground, as Libya's dictator Colonel Muammar Gaddafi attempts to crack down on protesters to his regime.
The BBC's Radio 4 Today programme reported a contingent of SAS troops had been put on standby for "emergency deployment" to Libya to help rescue British nationals stranded in the country. The Ministry of Defence refused to comment, saying it did not discuss special forces operations.
Oil worker Bryan Richards escaped from Libya on what he was told was the Polish President's official plane after being offered one of 50 seats. Speaking to the BBC Radio 4 Today programme from Warsaw, he said: "I am not quite sure how it came about but we had a call saying that there's a Polish plane going with 50 seats. 'Does anyone want one?' It was a bit of no-brainer really. I am in Warsaw. I am out of the sand and into the snow."