The Supreme Court will sit in Galway next March to hear an appeal against a decision of An Bord Pleanála to approve the first phase of an €850 million data centre in Athenry.

Last May, Apple decided not to go ahead with the Athenry data centre project, but the court's decision could affect how the board would consider a similar development.

Two objectors to the permission appealed to the Supreme Court after the High Court dismissed their challenge to An Bord Pleanála's decision.

The appeal was brought by Sinead Fitzpatrick who lives near the proposed data centre, and Allan Daly of Athenry.

The objection was opposed by An Bord Pleanála and the State.

Today, the Supreme Court issued a judgment setting out the precise issues to be addressed in the appeal.

The court had to first decide on these issues because An Bord Pleanála had complained that different issues were being pursued in the Supreme Court to those argued in the High Court by the objectors.

Chief Justice Mr Justice Frank Clarke said the court, as well as deciding the scope of the appeal, had also decided it was not necessary, at this stage, to make a preliminary reference of questions to the Court of Justice of the EU for determination.

However he said when the full appeal is being heard the court may decide to refer a question to the CJEU.

It remains open to the parties to suggest, during the full hearing, that a reference is required, he stressed.

He also told the sides the appeal would be heard on 6 March in Galway as part of the Supreme Court programme of sittings outside Dublin. There is a link between this appeal and Galway, he noted.

The case arose after Apple got planning permission from the board on 11 August 2016 for a development of one data hall and associated grid connection at Athenry.

In today’s judgment, the Chief Justice said the central thrust of the appellants' case relates to the extent to which the board is obliged to assess the environmental impact of the balance of the Apple "masterplan" for eight data halls as part of the Board's obligation to carry out an Environmental Impact Assessment (EIA).

He did not see any prejudice would be caused to the board if the court explored the precise extent of the obligations on the board to consider the potential impacts of the remainder of the masterplan.

The appellants are entitled to argue the board is obliged to carry out a full EIA on the entire masterplan, "subject only to the limits of practicality", he ruled.

They were also entitled, as a "fall-back position", to suggest the board was obliged to assess environmental impacts in a manner that falls short of the appellants' primary case but which exceeds the EIA actually carried out by the board.

Once the court decides the board's precise obligations, it can consider whether the assessment actually conducted by the board fell short of those obligations, he ruled.

The appellants must now formulate their grounds of appeal in line with the court's rulings on the scope of the appeal.