Lawyers representing Fine Gael Cllr, Mr Liam Cosgrave, today called on the tribunal to "stand down" its investigation into allegations made by Mr Frank Dunlop.
Mr Michael O'Higgins SC, for Mr Cosgrave said the tribunal had failed to investigate Mr Dunlop's credibility as a witness, given the fact that he lied when he first gave evidence in April 2000.
Mr O'Higgins asked the tribunal why Mr Dunlop had been questioned for 7½ days without asking him why he had lied his initial evidence. Mr O'Higgins said the last day of Mr Mr Dunlop's evidence mentioned the issue for 30 minutes.
Cllr Cosgrave was supported by lawyers for other councillors accused of corruption. Counsel for the late Cllr Tom Hand, Mr Cormac O Dúlacháin accused the tribunal of operating a "witness protection programme" for Mr Dunlop.
The politicians are demanding access to Mr Dunlop's bank records and his private interviews with tribunal lawyers, which they claim could help clear their names.
Mr O'Higgins added there was prima facieevidence Mr Dunlop had committed a number of criminal offences, including perjury, corruption and fraudulent conversion.
He asked the tribunal whether these apparent breaches had been referred to the Director of Public Prosecutions and if not, it should explain why not.
Mr Dunlop has alleged he paid bribes to Mr Cosgrave and eight other politicians in return for their votes on the rezoning of land in Carrickmines in south Dublin. Cllr Cosgrave, who is alleged to have received at least £15,000, denies the claim.
Replying, Mr John Gallagher SC for the tribunal said many of Mr O'Higgins' points had already been dealt with in previous rulings by the tribunal. He stressed that Interviews conducted by tribunal lawyers were bound by confidentiality rules.