Former Rehab chief executive Frank Flannery has launched a stinging attack on the Oireachtas Public Accounts Committee, saying its behaviour in examining the organisation was an example of lawmakers acting as lawbreakers.

Mr Flannery, who was a long-time Fine Gael member and strategist, said the committee had been seeking headlines and pursuing vendettas under the cover of examining how money that went from the State to Rehab was spent. He accused committee members of attempting to run amok and of behaving in "an illegal and almost righteous fashion".

“This committee was set upon a lawless path and they were attacking the rights of citizens under our constitution,” he told RTÉ’s Today with Seán O’Rourke programme. “They knew they were doing it and I believe it was widely known in the system that it was going on but nobody was shouting stop.”

Earlier this week, the Oireachtas Committee on Procedures and Privileges (CPP) told the PAC that it did not have the power to compel Mr Flannery or former Rehab chief executive Angela Kerins, who faced hours of questioning by members prior to her resignation, to appear before it.

The CPP said that because Rehab was not audited by the Comptroller & Auditor General, the PAC did not have the legal authority to examine how it used public monies.

Mr Flannery said the PAC had been told this by its own legal advisers, yet “they deliberately decided to go against their legal advice and to pursue their vendettas against people and organisations even though they knew it was unlawful”.

He added: “When lawmakers become lawbreakers the country is in a very dangerous situation and the Committee on Procedures and Privileges has done, in my opinion, parliament and the committee’s system a very necessary service in putting a halt to this particular gallop.”

Mr Flannery denied refusing to attend the committee, saying he had not been invited in. He said he wrote to the committee after hearing members “yelling at me over the radio morning, noon and night” asking what information they wanted from him and how that fits within PAC’s remit.

“That’s information which any witness to any committee is fully entitled to. I have never received a reply to that letter,” he said, adding that he would have been happy to go before the committee if his questions had been answered, but was now glad he took a stand.

Mr Flannery said the nature of questioning Ms Kerins was subjected to was unrelated to the contracts Rehab won from the State but rather an “incessant personal attack”.

Put to him that the questioning was in the interest of transparency, Mr Flannery said the public was entitled to it but that the PAC was not entitled to break the law.

“Particularly if they are doing it for their personal aggrandisement and headline seeking and there is a strong suspicion that certain members of that committee were embarked on such a programme,” he said. “The fact that I was director of elections for Fine Gael and a trustee of the party is, in my opinion, not at all unrelated to their decision to haul me back after eight years of retirement and try and subject me to their particular form of inquisition.”

He said the PAC had no right to inquire into personal rights of citizens such as the pension he received from Rehab.

Asked about the fact that he received tens of thousands in fees from Rehab for consultancy services such as lobbying the Government after his retirement, Mr Flannery said the organisation got very good value for his contributions.

He denied there was anything “cosy” about a person with links to Fine Gael lobbying a Government of which the party was a member. He said a number of former ministers and civil servants were now working as consultants and stressed he had never worked for the State or been a politician.

Taoiseach Enda Kenny previously said Mr Flannery should not have been paid by Rehab to lobby ministers when he was a director of the charity.

Mr Flannery said he felt “pretty battered and bruised” by his experience with the PAC but that the damage done to Rehab’s reputation by the imbroglio was the “greatest agony in my life right now”.

Of his treatment by Fine Gael, which withdrew his access pass to Leinster House following controversy over his lobbying, Mr Flannery said he did not expect anything different as it was a political party with elections to fight and a Government to run.

During the episode, Mr Flannery resigned as a Fine Gael trustee, director of organisation and director of elections for the recent local campaign.

He described the organisation as “my good old delightful Fine Gael” and said he had put “sweat, blood and tears” into the party. The fact he is now outside Fine Gael was “ another serious damage done to me”, he said.