The Supreme Court has been asked to reconsider an issue in its judgment on public rights of way through the historic Lissadell estate in Co Sligo.
The court rejected claims by Sligo County Council that there were public rights of way over certain routes in its ruling in November last year.
Lawyers for the council asked the court to reconsider an issue in their legal submissions sent to the court last Friday.
The Chief Justice, Ms Justice Susan Denham, said it was "most unsatisfactory" that the issue was raised at such a late stage.
But she agreed to adjourn a decision on who should pay the costs of the case, estimated at around €7 million.
The court will sit again at a later date to give its decision on the council's request and to address the issue of costs.
Lawyers for the owners of Lissadell, Edward Walsh and Constance Cassidy, said the issue being raised by the council was utterly irrelevant.