Former minister for justice Alan Shatter has brought court proceedings aimed at overturning a finding that he had breached data protection laws when he divulged information about TD Mick Wallace on RTÉ's Prime Time.
Judge Alan Mahon directed that Mr Wallace be joined as a notice party to the case, which means he can be legally represented during the hearing.
His lawyers had said the outcome of the case could directly affect his rights and interests.
In May, Data Commissioner Billy Hawkes ruled that Mr Shatter had breached data protection laws a year earlier when he said during a Prime Time interview that Mr Wallace had been cautioned by gardaí for using his mobile phone while driving.
The commissioner found that at the time as the minister for justice he was a data controller in relation to this personal information and had failed to uphold his statutory duties under the Data Protection Acts.
The former minister apologised to Mr Wallace.
He later resigned over the findings of the Guerin Report into the handling of allegations of garda misconduct.
Today, the Circuit Civil Court was told that Mr Shatter is appealing the commissioner's decision and will ask the court overturn it.
He claims the commissioner erred in fact and in law in reaching his conclusions.
The case is expected to be heard in October.