Denis O'Brien has begun another legal challenge in the High Court against the Moriarty tribunal.
The founder of Esat Digifone is seeking a judicial review of aspects of the tribunal's continuing inquiry into the State's 1995 second mobile phone licence competition.
The case was mentioned earlier this week in the High Court and was adjourned to next Thursday.
Mr O'Brien is also appealing to the Supreme Court an earlier High Court decision not to grant an order preventing the tribunal holding public hearings into a possible link between former government minister Michael Lowry, and a property deal involving the Doncaster Rovers stadium in Doncaster.
The latest application for a judicial review follows a ruling by tribunal chairman Mr Justice Michael Moriarty last month to continue with the inquiry into the licence competition.
Mr O'Brien, Dermot Desmond and Norwegian company Telenor - all former shareholders in Esat Digifone - had made legal submissions to Mr Moriarty calling on him to abandon the inquiry. Mr Lowry also made a similar submission.
The four parties argued that without evidence of a Danish consultant, Michael Andersen, the tribunal would not be able to conduct a full and proper inquiry into the competition.
Mr Andersen, a consultant who played a key role in the licence competition, is refusing to come to Dublin to give evidence.
There were also complaints that parties to the tribunal had not been made aware that it had commissioned a report on the competition from economist Peter Bacon.
Following Mr Justice Moriarty's ruling, Mr O'Brien issued to The Irish Times an unprecedented public criticism of the tribunal.
The tribunal is investigating whether Mr Lowry interfered with the competition process, to the benefit of Esat Digifone.
"Either the process was interfered with or it was not. All the evidence given is that it was not. That should be the end of it," Mr O'Brien said in his statement.