Michael Lowry has accused the Moriarty Tribunal of "paranoia" ahead of a two-day Dail debate on its report.
The defiant TD was today preparing to launch a blistering attack on the tribunal amid accusations that Taoiseach Enda Kenny is dodging questions.
Opposition parties are furious that Communications Minister Pat Rabbitte could be left in the firing line, rather than Mr Kenny, for a questions-and- answers session on the tribunal fallout.
Fianna Fail and Sinn Fein want to press Fine Gael about its fundraising methods in light of the report, but the Taoiseach's contribution could be limited to a 30-minute statement.
On the other hand, Mr Lowry has demanded extra time to be allowed make a "personal statement" in which he will outline his defence against the tribunal's findings.
Using words like "insidious" and "indiscreet", Mr Justice Michael Moriarty said that it was "beyond doubt" that Mr Lowry imparted information that was of "significant assistance" in securing the country's second mobile phone licence to Esat Digifone.
The Tipperary North TD has already made a series of stinging allegations against the judge and the operation of the tribunal. He is now expected to go even further during the Dail debate as he will be able to use Oireachtas privilege to avoid any legal consequences from his statements.
In advance of the session, which begins at around 5pm today, he accused the tribunal of being gripped by a "bunker mentality".
Referring to fears that the tribunal offices in Dublin Castle may have been infiltrated and phones tapped, Mr Lowry said it was a "far-fetched suspicion of the tribunal and I wasn't a bit surprised today when I found it was unfounded.
"They obviously are suffering from some sort of bunker mentality and have a bit of paranoia."
Each of the party leaders will be allowed 20-30 minutes to outline their position on the report this evening.
Mr Lowry will then be given up to 50 minutes to put his case across and has also offered to answer any questions that other TDs may raise.
However, there is some anger that Taoiseach Enda Kenny or other ministers who were part of the Cabinet when the mobile licence was award in 1995 are not offering to answer questions.
Fianna Fail has accused Mr Kenny of "hiding".