Frank Flannery has described some members of the Public Accounts Committee as "wild" and "feral" in their inquiries into not-for-profit organisations.
He is one of two former Rehab Chief Executives that the spending watchdog wants to question about the running of the organisation.
Earlier this week, it was told by another Oireachtas committee that it could not force them to attend a hearing.
Mr Flannery has hit out at how he felt he and Angela Kerins were viewed by the PAC.
He said: "They saw witnesses as just play things, almost as slabs of meat with which they will have fun.
"Not only was this committee beginning an assault on the organisation I loved - it extended that assault to me although I'd retired eight weeks before - but they also expressed their desire to go and attack every organisation in the not-for-profit world.
"They would have created mayhem if somebody hadn't called a halt to their gallop."