The chairman of an inquiry into alleged historical abuse at care homes in Northern Ireland is to appeal a ruling that he unfairly denied legal representation to a victim.
Earlier this week High Court judge Mr Justice Treacy held that a bar had effectively been erected against the woman who claims she was molested by a "very high-profile figure".
But his former judicial colleague, Sir Anthony Hart, has now lodged a challenge to the verdict.
Judges in the Court of Appeal on Friday listed the case for hearing at the start of March.
The woman at the centre of the legal battle is due to give evidence at the ongoing Historical Institutional Abuse Inquiry.
The hearings in Banbridge, Co Down were set up in 2013 to investigate child abuse in residential institutions between 1922 and 1995. It has so far heard from nearly 100 victims and survivors of abuse, most of whom were in the care of the Catholic Church at homes in Derry and Kircubbin in Co Down.
Others were part of a state-approved child migrant scheme to Australia.
The focus has now shifted to the former Nazareth House and Nazareth Lodge in Belfast.
The woman behind the legal challenge claims she suffered years of physical, sexual and mental abuse while in the care of the Sisters of Nazareth. She also separately alleges that she was targeted by an unidentified high-profile figure.
But ahead of testifying she applied to have lawyers act for her at public expense. Mr Hart, a retired High Court judge, turned down her request after concluding it was not in the public interest because she was unlikely to be criticised during the inquiry or in its report.
Further reasons included the costs and her lack of “core participant” status.
In a judicial review challenge to the refusual, it was claimed the decision was unlawful and would give an unfair advantage to alleged abusers. Those accused of carrying out assaults and the institutions under investigation have been permitted legal representation.
In his judgment, Mr Justice Treacy asked: “Why should the perpetrator be placed in a materially more advantageous position in terms of legal representation, especially in circumstances where he already enjoys more participative rights to safeguard his interests?
“Can this objectively and as a matter of public law be regarded as fair?”
The judge held that cost implications do not remove the public law necessity for legal representation out of public funds if fairness requires it. He directed that the woman’s application should be remitted for the inquiry to reconsider and reach a decision in accordance with his ruling.
Mr Hart is seeking to have his determination overturned. It is expected that the woman’s evidence will be put on hold until the appeal is concluded.