Education minister John O'Dowd is facing a legal challenge over the planned amalgamation of two Fermanagh grammar schools.
Collegiate Grammar and Portora Royal in Enniskillen are set to be closed and merged into one new school.
But Mr O'Dowd's decision to approve the plans is now to be contested at the High Court.
Judicial review proceedings have been lodged on behalf of a pupil at Collegiate in a bid to have the move quashed.
Mr O'Dowd announced the closures last November.
At the time he insisted that he was focusing on the needs of children and young people, not on the institutions.
A petition against the plans, signed by 7,000 people, had been handed in at Stormont in an effort to preserve the schools.
Now the battle to stop any amalgamation has moved to the courts.
The legal challenge was originally brought in the name of a sixth form pupil at Collegiate.
But with the date of the planned merger now put back to September 2016, she will have left the school by that stage.
New papers will instead be submitted on behalf of a younger pupil, making the same case.
Lawyers are expected to argue that there was a failure to carry out a proper economic appraisal.
The impact on pupils possibly having to operate on a split site is also set to feature.
The Fermanagh Protestant Board of Education, trustees of the land at the 400-year-old Portora Royal - alma mater of Oscar Wilde, Samuel Beckett and Neil Hannon - are to be legally represented as a notice party in the case.
In court yesterday Tony McGleenan QC, for themninister, indicated that he was unlikely to oppose the case progressing to a full judicial review hearing.
He added: "We would need to see (details of) the new applicant to see if there are any idiosyncratic issues."
Mr Justice Treacy listed the case for a further review next month.
