Airlines including British Airways are proposing to sue the British Government for up to pound stg. 300 million ($742 million) to recover the losses incurred since extra security measures were imposed on the nation's airports last week.

They are hoping that the threat of legal action will force ministers to lift the restrictions on hand luggage, which have caused thousands of flight cancellations and delayed millions of passengers since an alleged terrorist plot was foiled.

British investigators yesterday were granted another week to question 23 suspects in the alleged plot to blow up as many as 10 trans-Atlantic jetliners.

A district judge ruled that 23 of the 25 people arrested since August 10 could be held without charge even as investigators continued to search several homes and businesses for clues to the foiled plot.

A suspect arrested on Tuesday was released on Wednesday without charge shortly after the hearing, Scotland Yard said. It did not say why or identify the person.

Another suspect was released without charge on August 11.

The ruling was the first major test of a new terrorism law that lets suspects be held for as long as 28 days without charge while investigators try to solidify their cases.

The hearing, which addressed the cases of 23 suspects arrested in Britain's initial sweep last week, was held behind closed doors and attended only by the suspects' lawyers, investigators and government officials.

Scotland Yard said that 21 of the suspects could be detained for questioning through to Wednesday, while another two could be detained until Monday. No reason was given for the difference in the length of time.

In the aftermath of the foiled plot, Britain's Home Office said yesterday it would press the rest of Europe to adopt Britain's tighter airport controls, which include a smaller maximum size for hand luggage and a ban on carrying liquids.

The European Commission said it was considering requiring all airlines flying to or from EU airports to collect detailed information on passengers and pass it to security services. A similar requirement by the US has resulted in long delays in the past week because each passenger has had to be checked and cleared before flights could depart.

The legal action being considered by the airlines focuses on section 93 of Britain's Transport Act 2000, under which the Government can be liable to pay compensation for losses resulting from its emergency directions.

Ryanair made the strongest threats against the Government but British Airways and EasyJet also said they were considering legal action.

Ryanair's head of regulatory affairs, Jim Callaghan, sent an email to a group of leading airlines outlining the case for compensation and encouraging them to take action.

The email refers to section 93 and says: "Ryanair intends to use this provision to put pressure on the Government to remove some of the illogical and unworkable restrictions at airports that are leading to large-scale disruptions and flight cancellations.

"We would invite other airlines to consider doing likewise."

A BA spokesman said: "Our lawyers are looking at this. It's certainly something worth exploring although I don't think the provisions of the act have been tested."

BA has also said that it is considering seeking compensation from BAA, the airports operator, for failing to have adequate contingency plans at Heathrow and Gatwick.

An EasyJet spokesman said: "We will consider whether either BAA or the Government has a case to answer. We have had to cancel 500 flights and put people up in hotels. Why should we have to pay for that?"

The British Air Transport Association, which represents 13 British airlines, urged the Transport Department to return to the international standard size for hand luggage.

BA is cancelling 19 short-haul flights from Heathrow overnight but expects to operate a full schedule today.

On Wednesday, a United Airlines Boeing 763 bound for Washington was diverted with a fighter escort to Boston after a woman passenger suffering from claustrophobia became disruptive.