The courts have no power to review the actions of the Committee on Members' Interests which suspended Ivor Callely from the Seanad, the Supreme Court has been told.
The submission was made on the second day of an appeal against a High Court decision, which found the committee had acted beyond its powers in its findings against Ivor Callely in relation to his expenses.
In 2010, the committee found he had misrepresented his normal place of residence as Cork for expenses claims and suspended him for 20 days.
Counsel for the committee, William Binchy, told the seven-judge Supreme Court the actions of the committee fell within parliamentary privilege.
The Constitution required the houses of the Oireachtas to set its own rules and standing orders, to regulate its own affairs and the conduct of its members, he said.
He said the mere fact that ethics legislation was invoked in the process did not collapse parliamentary privilege.
It was a zone of "non-justiciability", Mr Binchy told the court.
The power given to the Oireachtas was "awesome", in this respect but "once it is there, it is there," and the courts had to respect the potency of the power.
The fact that the committee's investigation was based on complaints by members of the public or those outside the Oireachtas did not change the fact that the committee was examining one of its own members.
Even if the decision of the committee was not fair, the courts could not review it, he submitted.
Mr Binchy said Mr Callely was not charged with a technical non-compliance with the definition of normal place of residence, rather with dishonesty or bringing the house into disrepute.
It was a broad criterion, he said.
Mr Binchy said the opinion of the man at the bus stop or the reasonable man was the important one in this case, not whether Mr Callely complied with a technical guideline on his normal place of residence.
It was quite possible to "dishonestly comply with the law", he said.
Counsel for Mr Callely, Michael O’Higgins, said he had complied with the expenses system to the letter. He did not design the system, he followed it.
He said Mr Callely had spent more than 60% of his time in Cork and had not claimed any expenses for the last three months of 2008 and 2009 as he was spending more time in Dublin.
The majority of his time was spent in Cork and no one had ever suggested otherwise, he said.
In announcing its determination the committee had “disapplied” the official Department of Finance definition of normal place of residence but it did not inform anyone of this fact, he said.
A new definition for normal place of residence was adopted as a new yardstick using a list of "links" to Clontarf.
The public at large was left completely in ignorance of this, Mr O’Higgins said. The public and the media looked at the result of the committee's findings, not the process.
Senator Callely could not have been expected to carry the transcript of the committee hearings around with him so if someone heckled him he could say there was more to it.
A finding of dishonesty was a matter of fact and could not be regarded as a political judgment as claimed in the High Court, Mr O’Higgins said.
The findings made by the committee had led to a most appalling media invective and had emboldened the media to write the most appalling things about Mr Callely, Mr O'Higgins said.
He added that Mr Callely had been accused of being a thief and a snake had been left in his porch.
The hearing will resume before the Supreme Court at a later date.