Businessman Denis O'Brien has received permission to appeal directly to the Supreme Court over the dismissal of his case against the Dáil and State over statements by two TDs in the House about his banking affairs.
Mr O’Brien is also appealing an order requiring him to pay the estimated €1 million legal costs of his failed High Court action.
His appeal will run in tandem with a separate Supreme Court appeal by former Rehab chief executive Angela Kerins against the rejection of her challenge over her treatment at two Dáil Public Accounts Committee hearings into payments to Rehab.
Both appeals raise similar issues concerning the constitutional separation of powers and the courts' ability to intervene in decisions and proceedings of Houses and Committees of the Oireachtas.
A hearing date for the two appeals will be set later but they will be case managed together in the interim.
An appeal to the Supreme Court may only be brought if that court considers a case raises issues of general public importance meriting such an appeal or the court considers an appeal is necessary in the interests of justice.
A three judge Supreme Court has agreed to permit Mr O’Brien an appeal on grounds of the importance of the issues raised.
The appeal is against the clerk of the Dáil, the Dáil Committee on Procedures and Privileges and the State.
His proceedings arose from statements made on separate dates in the summer of 2015 by Social Democrats TD Catherine Murphy and Sinn Féin TD Pearse Doherty after Mr O'Brien got court injunctions restraining RTÉ from publicising that information.
In her High Court judgment dismissing the case last March, Ms Justice Úna Ní Raifeartaigh held that what Mr O’Brien sought was prohibited by the separation of powers under the Constitution and would have a “chilling effect” on parliamentary speech into the future.
She upheld the core defence argument that Article 15 of the Constitution immunises Dáil “utterances” from suit or scrutiny by courts or tribunals. She later awarded the estimated €1 million cost of the action against Mr O’Brien.
