Judgment has been reserved in the Education Minister's appeal against the quashing of his decision to shut the first Catholic school in Northern Ireland trying for integrated status.
Earlier this year the High Court ruled that John O'Dowd relied on incorrect information that Clintyclay Primary was in financial difficulties when approving a proposal for its closure.
The verdict appeared to offer a reprieve to the small school outside Dungannon, Co Tyrone.
But lawyers for the minister have now mounted a challenge to the finding against him, arguing that it costs far more to run than others in Northern Ireland.
Senior judges were told yesterday that educational spending per pupil is up to 60% higher at Clintyclay.
The school's future has been plunged into doubt due to enrolment numbers that dropped below 30 children.
That led to the Council for Catholic Maintained Schools (CCMS) proposing it should close.
An alternative proposal advanced by the school's board of governors to change its management to grant-maintained integrated status was rejected.
At the time of the minister's announcement in October last year he said enrolment levels meant it was no longer sustainable.
Due to this long-term situation, transformation to integrated status was not regarded as a feasible option. The parents of Clintyclay then sought a judicial review, arguing that the closure decision should have been deferred until a full assessment of the transformation option was carried out.
Clintyclay had been the first Catholic school in Northern Ireland to attempt a switch to integrated status. In March the High Court held that the minister mistakenly took his decisions on the basis that the school was under financial stress.
The judge pointed out that rather than facing financial difficulties, the school in fact had a budget surplus.
Appealing the ruling yesterday, Tony McGleenan QC, for the minister, stressed how expensive it was to fund Clintyclay.
He argued that it may not be able to survive any change to a policy of providing financial help to schools with low enrolments.
"It doesn't have financial difficulties in the sense it has a small surplus," he said.
"But it costs a lot to run, and if small school support is withdrawn this school will be imperilled."
The barrister was pressed repeatedly by the three appeal judges for an explanation why papers before the minister described Clintyclay as having financial problems.
He contended, however, that the issue was "a distraction".
"The minister says the issue was enrolment and he's properly had regard to that," Mr McGleenan said. "In terms of financial matters, the minister was given full and accurate information. The suggestion he was misled is wrong."
Following submissions Lord Chief Justice Morgan, sitting with Lord Justice Weatherup and Mr Justice Deeny, confirmed they were reserving judgment in the appeal.