MILLIONS of Ryanair passengers across the UK could be in line for a payout after a landmark court judgment ruled the airline cannot limit the time allowed to claim compensation for flight delays.

Lawyers say the low-cost Irish carrier could be liable for payouts of around £610 million after the firm lost a test case at Manchester County Court.

The airline had argued claims for delays could be limited to two years under a clause in their terms and conditions small print. However, the rule under European law allows six years in England and five in Scotland.

The case was brought by lawyers for six delayed passengers who tried to claim compensation for delayed flights after five years and eight months, which Ryanair contested.

After a long-running legal battle, Judge Platts ruled Ryanair's rules fall foul of European Flight Delay law. Ryanair said it will appeal the decision.

Lawyers say the ruling in the case, Goel & Trivedi v Ryanair, stands to affect millions of air passengers.

They say if Ryanair had won, all airlines might have been able to put a two-year time bar on all existing and future flight delay claims.

Kevin Clarke, lawyer for Manchester law firm Bott & Co, who fought the case for the passengers, said: "We're delighted that the court has dismissed yet another argument put forward by the airlines to restrict passenger rights.

"The last twelve months have seen a series of landmark judgements obtained by Bott & Co on behalf of millions of passengers and this is as important as any of those that precede it.

"The Supreme Court decision last year said passengers have six years to bring a claim. That is a definitive, binding, clear judgment from the highest court in England and Wales."

He added that there was no reason to think the ruling would not apply North of the border as it dealt with a European directive which applied to each member state.

He said: "This should have concluded matters but unfortunately Ryanair have been able to tweak the argument; we found ourselves running a complicated court case arguing the fine points of contract law.

"We fully expect the airlines to continue to fight these cases but we are prepared to hold them to account in each and every instance where the law says compensation is payable, and with the courts continuing to find on behalf of consumers we've real cause to be optimistic that passengers will receive the compensation they are entitled to."

However, Ryanair said they will contest the ruling.

In a statement, the firm said: "We note this ruling which reverses Lower Court orders that a two-year time limit for claims is reasonable.

"Since we believe a six-year time limit for submitting such claims is both unnecessary and unreasonable, we have instructed our lawyers to immediately appeal this ruling."

Richard Lloyd, executive director of consumer champion charity Which? said: "This case is a huge victory for consumers and should deter other attempts to shorten the six-year time limit for seeking redress.

"It's about time that airlines hold their hands up and pay compensation where it is due.

"We are urging people to hold their airline to account and claim the compensation they are rightly owed if they have a lengthy delay and the airline is at fault."

A recent investigation by Which? found more than 9,000 flights in the UK are delayed for three hours or more over a 12-month period to May 2015, which could mean around 900,000 passengers are potentially eligible to receive compensation.