The Supreme Court is due to begin hearing an appeal this morning against the dismissal of Denis O’Brien’s legal action against the Dáil and the State.
It has been just over a year since the High Court refused to intervene in a case that arose from statements made by two TDs under privilege.
Mr O'Brien claims Deputies Catherine Murphy and Pearse Doherty abused their powers when they revealed details about his private business dealings with the IBRC.
He asked the High Court to reprimand them, but a judge ruled against him last year.