Former Justice Minister Alan Shatter is claiming in court that the Data Protection Commissioner prejudged a complaint that he unlawfully divulged information about TD Mick Wallace on RTÉ's Prime Time.
He is appealing against the decision which arose in relation to penalty points when he revealed in May 2013 that Mr Wallace had been cautioned for using his mobile phone while driving.
The court has heard Mr Shatter acted in the public interest by revealing on Prime Time that Mr Wallace had been a beneficiary of garda discretion on penalty points.
He believed he was defending the integrity of the force - however the disclosure resulted in a complaint by Mr Wallace to the Data Protection Commissioner, Billy Hawkes.
Last May, the Commissioner found Mr Shatter had broken data protection laws by revealing this personal information - a decision that is now being appealed.
Mr Shatter's lawyers claim there is evidence from an interview the Data Protection Commissioner gave to RTÉ last year that he prejudged the issue.
The court has also heard that Mr Shatter's side will fight claims from the Commissioner's lawyers that he no longer has the legal standing to take the case because he is no longer the Justice Minister.
The hearing is to last a day.
