Denis O'Brien has issued legal proceedings against the houses of the Oireachtas and the State in the wake of Dáil comments about his banking arrangements with IBRC.

The comments, made by TDs Catherine Murphy and Pearse Doherty, followed a High Court injunction stopping RTÉ broadcasting information about the businessman's dealings with the nationalised bank.

Mr O'Brien's barrister Michael Cush today told High Court President Nicholas Kearns that his client wants to establish the 'correct demarcation between the role of the Oireachtas and the courts'.

He said the proceedings, which were issued today, raise important issues.

President Kearns has agreed to a preliminary hearing on July 1.