A jury has been sworn in at the High Court for a defamation case against RTÉ by a Sinn Féin member and former councillor.
Nicky Kehoe, a political manager for the party, claims he was defamed in an RTÉ radio programme on 24 October 2015.
Mr Justice Bernard Barton told members of the jury panel the plaintiff was a political manager and very prominent member of Sinn Féin who says he was defamed during a broadcast of the Saturday with Claire Byrne programme.
The jury was told the programme contained a discussion between Labour's Joe Costello and Sinn Féin's Eoin Ó Broin.
The subject of the discussion focused on Mr Kehoe and Dublin City Council.
The judge said Mr Kehoe claims that during the discussion, Mr Costello said Mr Kehoe was a member of the provisional IRA army council, an illegal organisation, and that he regularly attended meetings and directed Sinn Féin councillors how to vote.
Mr Ó Broin was also involved in the discussion.
The judge said Mr Kehoe says the conversation was hugely defamatory because what the listeners would have heard was that he was a member of the army council and that he controlled like a puppet master how the Sinn Féin councillors voted on matters on the city council.
Judge Barton told the jury that RTÉ denied the words used were defamatory and also says the live broadcast was on a matter of public interest and is protected by law.
He said Mr Kehoe was looking for significant damages, while RTÉ was saying it had a complete defence at law to all of the claims.
He said both sides in the case must receive a fair trial.
He told the jury panel that anyone connected to either party in the case or who felt they could not impartially decide on the evidence should not serve on the jury.
The case gets under way tomorrow and is expected to last six days.