A lawyer defending Labour MP Peter Hain against claims that he "scandalised a judge" has challenged whether the offence still exists.
David Dunlop, counsel for the former Northern Ireland Secretary, said the legal action against him had "highly significant" implications for free speech and questioned whether the case had any basis in common law.
The action, taken by the Northern Ireland Attorney General, John Larkin, stems from comments made by Mr Hain in his autobiography, Outside In.
The case has attracted criticism from both sides of the Commons, with more than 120 MPs signing a motion calling for the proceedings to be dropped. David Cameron said exchanges between judges and politicians were part of modern democracy and should be kept "as far as possible out of the courts".
At a preliminary hearing at Belfast High Court yesterday, Mr Larkin said that citizens were entitled to have confidence in the justice system. He declared: "The fair criticism of judges and judicial decisions is not only quite clearly a right, there are also occasions when there may be a duty to do it."
But while not arguing all criticism of judges was contempt of court, he said criticism which undermined public confidence in the administration of justice should not be permitted.
For Mr Hain, Mr Dunlop said he wished to examine whether the "archaic" offence still existed, and questioned whether the action complied with the European Convention on Human Rights. The case will be heard in full on 19 June.