Leading members of the Government and Opposition have united in condemnation of businessman Denis O'Brien's bid to sue the members of the Oireachtas Committee on Procedure and Privileges (CPP).

Minister for Transport Paschal Donohoe said yesterday that the rights of the CPP were a cornerstone of democracy and other senior political figures expressed grave concern about the case.

Mr O’Brien has accused the committee of breaching his constitutional rights and interfering with the role of the courts and has sued the members personally.

He has also named Ceann Comhairle Seán Barrett and Attorney General Máire Whelan in the case.

Mr O'Brien took the decision to sue the committee after it ruled that Independent TD Catherine Murphy and Sinn Féin TD Pearse Doherty had not abused privilege when they made claims against him in the Dáil.

In proceedings before the High Court, Mr O'Brien is seeking a declaration that the 10 TDs on the committee are guilty of an "unwarranted interference with the operation of the courts and have caused or permitted a breach" of his constitutional rights.

Personal rights

The businessman said article 40.31.1 of the Constitution guaranteed to respect, defend and vindicate the personal rights of the citizen.

Mr O'Brien's solicitors, William Fry, said this had not been not upheld by the Dáil committee.

The businessman said the decision by Ms Murphy and Mr Doherty to make allegations against him in the chamber was an attempt to "determine in whole or in large the case pending before the courts against RTÉ".

Mr O'Brien had been pursuing a High Court injunction against RTÉ preventing it from broadcasting a report about his personal banking arrangements with the Irish Bank Resolution Corporation.

Legal summons

In the legal summons, Mr O’Brien said by allowing TDs to make the “utterances” in the Dáil chamber, the committee had failed to enforce the sub-judice rule and so had interfered with the courts’ role.

He is also challenging the findings of the committee that Mr Doherty and Ms Murphy did not abuse Dáil privilege when making the claims.

Mr O’Brien, who is seeking costs for his case, said this conclusion had been reached without any evidence that the TDs had acted in good faith, and had breached his right to fair procedure.

The committee was served with the summons on July 14th but made members aware of it only last Friday. Each member, including Mr Barrett and Government Chief Whip Paul Kehoe, is named in the case.

Mr Donohoe yesterday said he supported the committee members. “Privileges available to members of the Oireachtas are an absolutely essential cornerstone to how democracy operates,” he said.

“Public representatives when they are elected to the Oireachtas have abilities that are available to them in terms of speaking about things that matter to our country.”

Sinn Féin leader Gerry Adams said TDs must be able to question the actions of the powerful and the privileged "without fear or favour".

On Monday, Fianna Fáil leader Micheál Martin said the action was "a very serous threat to democracy."