Fianna Fáil TD John McGuinness said the changes could see the committee, which monitors state spending, being taken over by government parties and stripped of its independent role.
He accused the Government of “stacking committees” with government-controlled politicians and also said the new plans to change the structure of committees were a “shambles”.
The outgoing Government announced earlier this week that it would introduce reforms for Oireachtas committees and the Dáil before the general election. None of these, though, would be enacted until the next administration takes over.
One reform would see the chairs of Oireachtas committees selected by the so-called d’Hondt system, which would see those positions allocated on the basis of Dáil representation. The Coalition say this reform would guarantee opposition TDs more power in the next Dáil, as under the current system, the Government decides most of the chairs.
However, an exception is the position of chairman of PAC, which traditionally is given to an opposition TD.
Mr McGuinness said the planned d’Hondt selection system was a “cosmetic exercise” and in reality was “nothing short of a three-card trick”.
“This new system would be a complete and utter shambles.”
He said real reform for PAC would be to empower its members as well as the comptroller and auditor general, who monitors spending by departments and reports to the committee.
“At every attempt they [the Government] have stopped us from doing that. Give members complete control, with no political interference, to allow the opposition of the day, to have a real input into examining public expenditure during and after, should an issue arise.”
Mr McGuinness highlighted how Fine Gael, in opposition, had used the PAC to independently probe spending by Fianna Fáil-led governments.