A three-judge High Court will today begin hearing a challenge by gardaí to the inquiry by an Oireachtas subcommittee into the shooting dead of John Carthy in Abbeylara, Co Longford.
Among those who have sworn affidavits in the proceedings for the Garda applicants are a former minister for justice, Mr Patrick Cooney, and a former secretary of the department of finance, Mr Seán Cromien.
It is thought the hearing will raise important issues with consequences for the work of all Oireachtas committees, including the capacity of the Houses of the Oireachtas to hold inquiries.
The President of the High Court, Mr Justice Morris, is presiding over a divisional court, which includes Ms Justice Carroll and Mr Justice Kelly. The hearing is expected to last two weeks.
While dealing with preliminary matters last week, Mr Justice Kelly reserved to the full three-judge court the issue of whether to allow lawyers for the gardaí to cross-examine the chairman of the Oireachtas subcommittee, Mr Seán Ardagh.