The Advertising Standards Authority has called on the Office of Fair Trading to investigate Ryanair following repeated infractions of its code.

Within the last two years the ASA has investigated and found the budget airline in breach of the Committee of Advertising Practice Non-broadcast Advertising Code on seven separate occasions.

Some of the ways in which the airline has broken the code have included exaggerating flight availability or unfairly denigrating rivals.

Now the OFT is reviewing Ryanair’s behaviour and has the option to resort to legal action should it be deemed necessarily.

ASA director general Christopher Graham said: “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.”

The airline has retaliated by referring the ASA to the OFT citing it for unfair procedures, bias and making factually untrue rulings during the previous two years.

Ryanair head of communications Peter Sherrard said: “Fairness and impartiality is the least that advertisers should be entitled to expect from an unelected self-regulating quango like the ASA and its impartial director general. Sadly Ryanair has received neither over the past two years from the ASA.”

The OFT refused to comment on either case while they are being investigated.

However, the OFT has already investigated Ryanair once this year over its failure to advertise airline tickets at their single final price.