Businessman Denis O’Brien wants to have evidence from a US constitutional law expert heard in his forthcoming High Court action alleging statements made by TDs in the Dáil about his banking affairs are not absolutely privileged.

Mr O’Brien, who will give evidence in the case himself, claims there is no such absolute privilege on grounds including utterances in the House must not usurp the judicial domain and must be linked to the legislative process.

If the claims are upheld, it has major implications for Oireachtas proceedings.

A pre-trial application, to have the court admit into evidence a 60-page report from Prof Laurence Henry Tribe of Harvard Law School, was made on Thursday by Michael Cush SC, for Mr O’Brien.

Mr Cush said this was a “unique and important” case based on “stark” facts concerning Dáil statements made by Social Democrat TD Catherine Murphy and Sinn Féin TD Pearse Doherty about his client’s banking affairs.

Evidence as to US law was relevant to the issues raised, he argued. It would be “appropriate and helpful” to look at authorities from other jurisdictions and the issue for examination was the interplay between the various pillars in a democracy.

‘Constitutional convention’

Issues relevant to this case were shared with other jurisdictions, he said, such as the explicit separation of powers written into the constitution, he said.

Sara Moorhead SC, for the Dáil Committee on Procedure and Privileges, and Maurice Collins SC, for the State, argued there is no provision under which the Irish courts can hear such evidence.

Prof Tribe’s evidence has no relevance to Irish constitutional law. If US law was deemed to be relevant then so too could precedent from several other countries and Mr O’Brien’s case could turn into “a constitutional convention” if such evidence were admissible, Mr Collins argued.

There is “simply no US authority that could be seen to bear directly on the issues in these proceedings”, he said.

The issue in Mr O’Brien’s case was one of Irish, not US, law and the report at issue was “not a report on US law. It’s purpose is to advocate a result in these proceedings.” To say his views on US law should be taken as evidence on Irish law was “simply not admissible”.

Decision later

Mr Collins added it seemed, in counsel’s experience, every case by Mr O’Brien was described as “unique and important”.

The President of the High Court, Mr Justice Peter Kelly, said he would give his decision as to whether the evidence was admissible on a later date. The judge previously refused an application by Mr Cush to have the action, fixed for hearing on November 29th, heard by a three-judge High Court.

Mr O’Brien has claimed utterances by Deputy Murphy and Deputy Doherty in the Dáil in May and June 2015 respectively breached his rights in forcing him to concede in the High Court, in June 2015, a script which he sought to prevent RTÉ publishing concerning his banking affairs with IBRC, and which he had successfully injuncted, and it was by then in the public domain.

The CPP, in response to complaints by Mr O’Brien, held neither Deputy had breached the standing orders governing debate in the Dáil.