A High Court challenge to regulations allowing hotels to have indoor dining while other restaurants are limited to outdoors has been adjourned to next month.

The Restaurants Association of Ireland along with three restaurants are challenging what they say are "irrational" regulations.

In a sworn statement, the RAI chief executive Adrian Cummins said its members have been "greatly disadvantaged and are incurring major economic loss by reason of the irrational regulations".

He said it was his belief the Minister had acted beyond his powers in making regulations which he described as discriminatory and disproportionate. He also said they were impossible to implement and were lacking in certainty and fairness.

Senior Counsel Michael McDowell told the judge he was not pressing for the case to be heard and decided by 5 July but said even if lifted by then, there are issues about the legality of the regulations if the situation worsens in the future.

The applicants want an opportunity to argue that the regulations are unlawful and should not be repeated, he said.

He said while they fully accept the need for restrictions to stop the spread of Covid-19 they will argue the restrictions on restaurants, compared to those on hotels and B&Bs, are irrational and disproportionate, amount to unjustified interference with their economic interests and in excess of the Minister's powers.

Preventing members of the public from entering restaurants except to order and collect food was irrational, disproportionate and unjustifiable as was preventing outdoor diners from using the toilets of the restaurant, he said.

He said the regulations allow non-essential retail, gyms and cinemas and the use of outdoor sections of bars and other premises for consumption of alcohol without time constraints, while prohibiting all indoor dining in non-hotel commercial restaurants, he said.

Permitting indoor dining for 25 attendees at a wedding reception while not permitting an indoor dining post-funeral event for a similar number is irrational and unjustifiable, he said.

The regulations also fail to take account of the size and ventilation of facilities and it was irrational that small dining rooms in less ventilated hotels can operate, while bigger, better ventilated restaurants could not, he added.

The case has been taken by the representative body for the restaurants of Ireland; Boxty House Ltd, a restaurant operator of Temple Bar, Dublin 2, Esquires Coffee Houses Ltd, which operates cafes and has registered offices at Ballybrit, Galway; and Sarsfield Taverns Ltd, which operates a pub/restaurant and has registered offices at Mallow Street, Limerick.

Today, Mr Justice Charles Meenan said the Minister for Health should be notified of the application for judicial review.

The judge noted it was the Government's intention to lift the restrictions on 5 July if the public health situation allows.

He adjourned the case to 8 July and said all will be aware of developments by then.

The Minister must outline his objections by 2 July.