Publican Charlie Chawke has petitioned the High Court to quash the finding of non-cooperation against him in relation to the Mahon Planning Tribunal.
Mr Chawke claimed the Mahon Planning Tribunal breached his rights in concluding he had not cooperated with it, arising from his evidence about a financial "dig out" for former taoiseach Bertie Ahern.
He argued that the finding was made in breach of natural justice and outside the powers of the tribunal.
His judicial review challenge arises from his evidence to the tribunal that he, along with seven other businessmen, contributed IR£2,500 each in a December 1993 "whip around" to help Mr Ahern as he had problems with legal bills following his marital separation.
The money was repaid with interest by Mr Ahern in 2006 and later passed on to a charity, the tribunal heard.
Mr Chawke claims he was never given an opportunity, before the tribunal issued its final report and findings, to address the tribunal's conclusion that his evidence in relation to the money was false.
He claims he was not given the chance to do so either while giving evidence himself, by cross-examining other witnesses or by making submissions in relation to the tribunal's eventual findings.
The finding of non cooperation also has consequences in relation to legal costs orders which the tribunal has yet to make, he says.
In opposing his action, the tribunal argues, among various arguments, that Mr Chawke was legally represented at the tribunal hearings and denies that he became aware of the tribunal's findings for the first time in 2012.
Opening Mr Chawke's case yesterday, Brian O'Moore SC said the findings against his client were flawed and showed pre-judgment of the matter.
The tribunal did not tell Mr Chawke's lawyers he was in jeopardy of a finding that his evidence was untruthful and this was a clear breach of his rights, as has been decided in a number of other cases, counsel said.
"He is a victim of an egregious breach of natural justice by the tribunal", counsel submitted.
The hearing continues before Ms Justice Marie Baker.