Two UK airlines have cancelled flights in and out of Libya as Britons are being advised to leave the strife-torn country on commercial flights.
British Airways and British Midland International scrapped their service to the capital Tripoli on Tuesday. Others are thought to have followed suit.
Most of the 3,500 Britons resident in Libya are thought to have already left.
The Foreign Office said it was looking at chartering an aircraft for Britons unable to get a commercial flight home.
Meanwhile Italy, Greece and the Netherlands are sending transport planes to Libya to get their citizens out. Austria and Portugal have already done so.
No cash machines
One Briton, whose relatives are stuck in Tripoli, described chaotic scenes at the airport and said the UK government was doing nothing to help them.
The woman, who asked not to be named, told BBC News: "The Foreign Office has told everyone to leave Libya, however there are no flights available.
"My brother-in-law was advised to take cash to the airport as the cash machines are not working. He has bought six tickets with cash and has not been able to get on any flight."
There is some doubt over whether other UK-Libya flights are still operating, including the Afriqiyah Airways service which normally links Gatwick with Tripoli.
The airline's offices in Libya were unreachable on Tuesday, but a reservations agent working on behalf of the airline told the BBC that the flight was operating normally. However a spokesman for Gatwick airport said it was subject to delays.
Manchester Airport has a daily connection with Tripoli, operated by Libyan Airlines, but an airport spokesman said that flight had been cancelled.
"It operated yesterday - it brought in around 50 people and around eight passengers left on it. But the handling agents have told us it's been cancelled today," he said.
Calls to the Libyan Airlines office at Heathrow were not being answered.
With normal scheduled flights facing severe disruption, the Foreign Office said it was looking into the options for chartering an aircraft to fly UK nationals out of the country.
Relatives of British people currently working and living in Libya told the BBC of their concern for their relatives.
Julie O'Shea, from Uddingston in Glasgow, said she was worried about her father, an oil worker.
"My dad is stuck in the Amal desert in Libya and fears for his life. We haven't heard from him since last night. He is currently in staff quarters.
"Even though there is security, they have been targeted by looters and have had all vehicles stolen so there's no way out even if they wanted to leave."