The Supreme Court has agreed to hear an appeal by objectors to Apple's planned €850 million data centre in Athenry, Co Galway.

Late last year lawyers for local residents Allan Daly and Sinead Fitzpatrick asked the court for permission to appeal an earlier decision by the High Court that paved the way for the development to proceed.

In its determination, the Supreme Court says the central issue it has to decide is whether An Bord Pleanála was required under law to consider the impact of an expansion of the project to include up to eight data halls, rather than the one hall for which permission was granted.

An Bord Pleanála has argued that the earlier High Court decision to reject an appeal by the objectors was simply an application of well established principles of European law to the facts of the case.

But the Supreme Court says it is not persuaded that it can safely be said that there might not be a point of general importance concerning the application of the broad general principles identified in the case law to a category of case such as this.

As a result it has given permission for the appeal to proceed.

The court says at this stage its decision should not be taken to in any way indicate that such a point necessarily arises.

But rather, it states, one of the matters which it will have to consider is whether such a point does arise, and if it does then whether it is obliged to refer the case to the European Court of Justice.

A preliminary hearing at which directions will be given by the court to both sides about how the case should proceed will take place next week.

The court says it is aware that the proceedings have taken some time and it is anxious that they proceed "with all due expedition."

Last October, the High Court cleared the way for the €850 million centre to go ahead, dismissing a judicial review taken by Mr Daly and Ms Fitzpatrick of An Bord Pleanála's decision granting it planning permission.

The following month, the High Court refused to give the objectors permission to appeal its decision to the Court of Appeal.

That meant the only remaining avenue for appeal was directly to the Supreme Court and in December the objectors lodged an application asking the court to admit their case for full hearing.

Apple first announced plans to construct the data centre on a greenfield site at Derrydonnell Woods near Athenry in February 2015.

Construction of the first phase promised to generate 300 temporary jobs, with up to 150 permanent staff required to run it.

The following September, Galway County Council gave permission for it to proceed subject to conditions, but that decision was subsequently appealed to An Bord Pleanála.

Following oral hearings the planning authority confirmed the permission in August of last year.

Amid the delays, Apple has remained tight-lipped about whether or not it still intends to proceed with the data centre.

At a meeting last year with the Taoiseach in the US, Apple chief executive Tim Cook stopped short of committing to begin the project if final permission was to be granted.