The terror alert crippled airports in the UK last week

The Irish group said it may take action under the Transport Act 2000, which says the government can be liable for losses triggered by emergency actions.

A spokesman for the budget airline added it had been in touch with other airlines about its plans.

Any claims would be resisted on the grounds the measures were taken under a different act, the government said.

A Department for Transport spokesman said it had no case to answer as the security measures were imposed under the Aviation Security Act 1982.

According to reports, Ryanair could sue the government for up to �300m to compensate it for losses incurred when airport security was stepped up last week.

'Unworkable'

In an email to other airlines inviting them to follow suit in demanding compensation, Ryanair said it hoped the threat of legal action would push the government to "remove some of the illogical and unworkable" restrictions at airports.

However, British Airways said it would not be pursuing the government for any claims.

Instead, BA is focusing on possible action for compensation from airports operator BAA for cancelled flights.

Analysts claim the airline could lose as much as �40m in revenues as a result of delays triggered by security restrictions imposed in the wake of last Thursday's security scare.

More than 700 BA flights have been cancelled at Heathrow after strict requirements to check in hand luggage caused delays.