“One cannot rely on the Constitution to subvert the Constitution.”

So said Denis O’Brien’s barrister as he set out his client’s stall yesterday, portraying him as a noble defender of the proper constitutional order. In no way did O’Brien wish to curb the right of elected representatives to debate what was properly in their domain and in the public interest.

This was not a case about parliamentary privilege, argued Michael Cush SC; this was a case about the separation of powers. He made clear that the essence of O'Brien's pleadings to the judge was that the judiciary should protect their patch from an unhealthy, if not unholy, intrusion by two TDs whose transgressions had gone unpunished by the Dáil's own watchdog.

If the businessman is to win the day, he may end up having to thank for his success a precedent established by Sinn Féin, together with comments by the Chief Justice, Ms Justice Susan Denham, and what Mr Justice William McKechnie had to say about former senator Ivor Callely, whose expenses fiddling landed him in jail.

On the opening day of what is expected to be a six- or seven-day hearing of the action O'Brien has launched against the Dáil Committee on Procedure and Privileges (CPP) and also the State, barristers outnumbered members of the public spectating in Court 29 of Dublin's Four Courts.

Among them sat a glum looking James Morrissey, O'Brien's combative spokesman, who spent much of his time tapping away on his mobile phone.

No damages sought

O’Brien’s action is not in pursuit of damages; nor is he looking for anyone to be jailed, were that even possible.

Rather, he wants a declaration that Social Democrat TD Catherine Murphy and Sinn Féin TD Pearse Doherty exceeded what was right when, in the Dáil in May and June 2015 and, in Ms Murphy's case, in a press statement and on Twitter, they, as O'Brien would have it, usurped the proper functions of the courts and denied him his rights as a citizen.

Quoting from the preamble to the Constitution, which notes that all actions of both “men and States” derive their authority from “the Most Holy Trinity”, Cush dwelt on the preamble’s imperative, to assure “the dignity and freedom of the individual”.

He then set about his argument in clear, calm and logical steps.

He said O'Brien had been seeking to protect the confidentiality of his banking arrangements with IBRC and related communications with its liquidator, Kieran Wallace. To achieve this, he obtained a court injunction making publishing that information off-limits to RTÉ – and other media.

“Everything that the case set out to achieve was undone by Deputy Murphy,” he said of the TD’s comments in the Dáil on May 6th. Then, on June 9th, Doherty gave, again in the Dáil, “by far the most detailed” account of O’Brien’s banking affairs.

“The game was up,” said Cush in reference to O’Brien’s efforts to keep matters confidential. The TDs had undone his legal action, “and that’s the trespass”, he said.

What some in the media remember as legal threats from O'Brien about reporting comments in the Dáil, Cush referred to as a weekend of "confusion" before the High Court clarified matters.

Later in his submission to Ms Justice Úna Ní Raifeartaigh, Cush sought to assure her it was "not an issue in this case" that people were being denied their Constitutional right to know what was going on in the Oireachtas.

That provoked a gravelly voiced intervention from Maurice Collins SC, appearing for the State. “Mr Cush is gliding over a lot of very important matters,” he said.

Undermining separation

Anticipating defence arguments that article 15 of the Constitution gave TDs privilege from being made amenable to any court, Cush suggested that this was an attempt “to use the separation of powers to undermine the separation of powers”.

To support his argument that at the core of O’Brien’s case is the separation of power between the legislature and the judiciary, counsel referenced a 1947 Supreme Court judgment striking down the Sinn Féin Funds Act. This, in effect, was a law instructing the courts not to give to Sinn Féin money lodged with the courts and to which the organisation claimed ownership.

In striking down the law, Mr Justice O’Byrne referred to the Constitution’s preamble about dignity and freedom – ideals that had to be given “life and reality”. The substantial effect of Murphy and Doherty had been to deny life and reality to O’Brien’s rights as an individual, argued Cush.

Ms Justice Denham had enunciated that the Dáil was not like the House of Commons; was not “a superior court of the nation”; and that Ivor Callely learned that it was “the function of the courts to determine the proper boundary between the legislative and judicial power”.

“And that is what Mr O’Brien is asking the court [here] to do,” pronounced counsel.