BUDGET airline Ryanair, the largest operator flying out of Stansted, is to be investigated by the Office of Fair Trading after a string of complaints by the Advertising Standards Authority (ASA).

BUDGET airline Ryanair, the largest operator flying out of Stansted, is to be investigated by the Office of Fair Trading after a string of complaints by the Advertising Standards Authority (ASA).

The ASA said its decision to refer Ryanair to the OFT followed “a catalogue of breaches” of advertising codes and unwillingness to comply with rulings.

But the conduct of the ASA will also come under scrutiny, with Ryanair having already approached the OFT with a formal complaint of its own against the authority, alleging a lack of impartiality and fairness.

The ASA said yesterday it had formally investigated complaints about Ryanair's advertisements and found them in breach on seven occasions over a two-year period.

It claimed the airline had persistently misled consumers by making exaggerated claims about the availability of flights at advertised prices and had advertised prices that did not include taxes and charges.

The airline had also made misleading and denigrating comparisons with competitors and had not stated restrictions that would exclude customers from taking up an offer, the ASA added.

A spokesman said the ASA rarely made formal referrals to the OFT, the most recent being in 2005, and only once it had established that an advertiser was unable to work within the rules.

Christopher Graham, director general of the ASA, said: “It is very disappointing, but absolutely necessary, that we have had to take this course of action.

“The ASA has given Ryanair every opportunity to put its house in order and ensure that its advertising adheres to the codes. Instead, they have continued to mislead consumers and denigrate competitors.

“We would prefer to work with advertisers within the self-regulatory system rather than call in a statutory body, but Ryanair's approach has left us with no option but to refer them to the OFT who will consider appropriate action.”

In is own complaint to the OFT last week, Ryanair claimed that the ASA had acted unreasonably in five of its recent findings against the company, the latest involving an advertisement offering two million £10 seats.

Ryanair said the complainant had provided no evidence of what flights and dates he had attempted to book and the company had therefore been denied the opportunity to prove there were £10 seats available.

The airline also claimed the ASA had acted unfairly in its handling of the complaint, by setting an “impossible” deadline for the submission of evidence, refusing to specify the evidence it was seeking and ignoring offers to provide further evidence as required.

Ryanair spokesman Peter Sherrard of Ryanair said: “In this latest ruling the ASA has denied Ryanair fair procedures, has ignored Ryanair's evidence and it has pursued a complaint which has no evidential basis whatsoever.

“This clearly confirms the ASA's bias, and blind determination to rule against Ryanair's adverts even in cases such as this where they accept that the two million seats offer was factually accurate.

“We are calling on the OFT to examine this catalogue of mal-administration, bias and incompetence by the ASA, and require in future that the ASA rules on Ryanair's adverts in an independent, impartial, fair and reasonable manner.”