The airline feels it has been unjustly dealt with by the ASA
Ryanair faces a probe by the Office of Fair Trading (OFT) after a string of complaints about its adverts.
The carrier has been referred by the Advertising Standards Authority (ASA) which has found Ryanair in breach of rules seven times in two years.
The ASA said exaggerated claims about flight availability at advertised prices, and prices that omitted taxes and charges had misled consumers.
Ryanair has already complained to the OFT about the ASA's rulings.
The low-cost carrier said that the authority's rulings against it had been "unfair, biased and untrue".
The ASA had "demonstrated a repeated lack of independence, impartiality and fairness", Ryanair added.
And it described the latest ruling - that it had made exaggerated claims about the availability of flights at advertised prices that did not include taxes and charges - as "the last straw".
"It's one of a number of advertisements where the ASA has demonstrated unfair procedures and bias and a clear anti-Ryanair agenda," said the carrier's spokesman Peter Sherrard.
"In this case, the complainant couldn't remember and couldn't provide any evidence of the flights he was trying to book.
"Most sensible organisations or adjudicators at that stage would simply have dropped the complaint and let it lie."
Other adverts which the ASA deemed to have broken rules included Ryanair:
- claiming its flight from London to Brussels was faster and cheaper than making the journey by Eurostar
- playing down the impact of aviation on the environment
- suggesting that stating that people buying tickets via an online agent were being "ripped off"
- using a model in schoolgirl-style clothes and a headline "hottest back to school fares"
And in a matter not dealt with by the ASA, French President Nicolas Sarkozy and his wife Carla Bruni won a case against Ryanair for using their picture without consent.
Many of Ryanair's ad campaigns have been controversial
Formal referrals to the OFT were rare, said the ASA's director general Christopher Graham - the last occurring in 2005
"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," he added.
"It is very disappointing, but absolutely necessary, that we have had to take this course of action.
Mr Graham added that Ryanair had been given "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," he said.
In February Ryanair shut down its website - in part to comply with an order by UK market regulators to make prices on its website clearer to consumers.
Last August, the OFT ordered 13 airlines to amend their websites to include "fixed non-optional" costs in their headline fares.