Ryanair is seeking permission to bring a High Court action aimed at setting aside international travel "restrictions" announced by the Government earlier this month.
Its application for leave for judicial review will be heard next month, the High Court directed on Friday.
Ryanair claims what it calls “restrictions” arising out of the Covid-19 pandemic are unlawful, a disproportionate interference with individual rights and are detrimental to its business.
The case concerns Government advice announced on July 21st concerning travel outside the island of Ireland, save for essential purposes, and for people to holiday at home in 2020.
The airline is also challenging the requirement for persons returning to the State from countries not on a designated green list to restrict their movements and self-isolate for 14 days.
Ryanair claims the "restrictions" are mandatory in nature and have the same effect as regulations which it says should have been, but were not voted on or approved, by the Oireachtas.
It claims they are unconstitutional and in breach of the 1970 and 2020 Health Acts, the European Convention of Human Rights and the European Charter of Fundamental Rights.
Ryanair's action is against the Taoiseach, Ireland and the Attorney General. Aer Lingus Ltd is a notice party to the action.
In correspondence opened to the court, the State says the measures challenged are advisory, not mandatory, and are not unlawful. It said there is no basis for a legal challenge against the measures.
It said its Covid-19 travel advisory notices in relation to non-essential travel are necessary, proportionate and transparent measures designed to deal with the global health emergency.
It said the green list of countries will be reviewed on a fortnightly basis based on advice from public health officials.
The airline, represented by Martin Hayden SC and Eoin O’Shea Bl, claims that what is involved is more than just advice from the Government regarding travel to and from Ireland.
Mr Hayden agreed with Mr Justice Charles Meenan its case is essentially that the Government has introduced effectively “mandatory” regulations “under the cloak of advices.”
This represents law making by the executive which ought to have been made law by the Oireachtas, counsel said. Without going through the proper processes the measures lack the proper checks and balances, counsel added.
Mr Hayden said the “restrictions” have a real effect on people including on ability to go back to work after returning to Ireland from a country not on the green list without going into a 14 day isolation.
There were also insurance implications and serious questions for the entire airline industry in Ireland, he said.
The airline wants the disputed measures quashed as unconstitutional and in breach of the EU Charter of Fundamental Rights and the ECHR.
Mr Justice Meenan said Ryanair had raised important issues and directed its ex parte application for leave for judicial review be made on August 12th in the presence of lawyers for the State respondents.
Given the urgency of the case, it may be possible to have a telescoped hearing, where both the application for leave and the challenge itself are heard at the same time, he added.