Ryanair has applied for a High Court judicial review to challenge a planning decision limiting the number of night-time flights at Dublin Airport.
The airline said the restriction, announced by An Coimisiún Pleanála (ACP) in July, amounts to "an illegal second movements cap".
Ryanair said the ACP ruling will "delay much-needed investment and growth at Dublin Airport".
"This unlawful cap, which artificially limits night movements, will block early morning pre-7am arrivals, which are vital for transatlantic landings between 05:00 and 07:00."
The company said the decision will "strangle transatlantic traffic, damage growth and short-haul connectivity at Ireland's main gateway airport".
In its ruling in July, the planning watchdog extended the operating hours of the new north runway to between 6am and midnight. Previously, there had been a ban on landing or taking off from that runway between 11pm and 7am.
As a result, the number of flights permitted at the airport, across its two runways, was increased from an average of 65 a night to 95 between 11pm and 7am, with a limit of 35,672 a year.
However, Ryanair has described the decision as "blunt and unlawful".
The airline today say the movement cap "reduces consumer choice, damages connectivity, and punishes investment, while doing nothing to encourage airlines who operate newer, quieter aircraft".
"Inexplicably, ACP fails to explain why it overruled the specialist airport noise regulator, Aircraft Noise Competent Authority (ANCA), who had already rejected a movement cap in favour of a night-time noise quota system, which operates at most EU airports, which would allow Dublin Airport to grow through use of quieter, more modern aircraft such as Ryanair’s new B737 aircraft."
"Sadly, Transport Minister Darragh O’Brien has continued to sit on his hands doing nothing to scrap the 2007 [passenger] cap, despite the Programme for Government pledging to abolish it as soon as possible."
"Now there is a second passenger cap at Dublin Airport damaging the growth of Irish tourism and jobs, while this do-nothing Government sits around pondering options as its preferred alternative to action."
The Chief Executive of the Ryanair Group has claimed that "these two artificial caps at Dublin Airport are unlawful".
"They are in breach the EU’s fundamental right to 'freedom of movement’ and they are also in breach of the EU - US ‘open skies’ flight agreement," Michael O’Leary said.
"Any competent Government would by now have already scrapped the original 2007 32 million traffic cap at Dublin Airport, given that the January 2025 government programme, promises to do so ‘as soon as possible’," he added.
Mr O’Leary said he believes "this illegal movement cap will damage existing transatlantic flights and shut off long haul traffic growth in Dublin, at a time when visitor numbers to Ireland are declining".
He said the airline "has no choice but to seek a judicial review of this latest unlawful planning stupidity".
'Stuck between a rock and a hard place' - daa
The operator of Dublin Airport said it has taken the "difficult decision" not to pursue judicial review proceedings in relation to the cap on night-time flights
The daa said it took the decision "following careful consideration."
It said its application to change "the highly onerous operating conditions" imposed on the new north runway was stuck in the planning system for five years, "creating prolonged uncertainty that was challenging for all stakeholders".
Daa said the ruling from An Coimisiún Pleanála in July brought "much needed clarity" on the night-time operating conditions at the airport.
"Unfortunately, the decision also included the imposition of a new night-time 'movement cap' which daa views as unnecessary on top of the new nighttime noise quota system".
The Dublin Airport operator said it will "regrettably" limit the airport’s growth and impact Ireland’s strategic connectivity as an island nation, "with negative implications for tourism, FDI and jobs".
However, daa said taking a judicial review against the North Runway Relevant Action (NRRA) would "open the airport to further prolonged uncertainty and hamper our ability to progress our application to lift the airport passenger cap through the planning system".
"This presented a real dilemma for daa and forced us to prioritise the Infrastructure Application."
Dublin Airport said it is on course to handle more than 36 million passengers this year and said it urgently needs a resolution to the passenger cap impasse.
The Chief Executive of the daa said they are "stuck between a rock and a hard place".
Kenny Jacobs said Dublin Airport urgently needs to get building the new piers and stands needed to manage 40 million passengers a year, but he said that can’t be done until its Infrastructure Application gets approved.
"The IA’s progress through the planning system has already been severely impacted by the uncertainty around the North Runway decision," he added.
"Now we have clarity about the night-time regime, we can get back to progressing the IA."
Mr Jacobs said the downside is that "we cannot tackle the new issue of the unnecessary night-time movement cap now and will have to do so in a future planning application".
"This is far from ideal and we note Ryanair’s judicial review proceedings but we have to prioritise getting the passenger cap lifted and building for the future."
