An important libel claim is due to be considered by the UK Supreme Court this week. But it’s not just the claimant’s reputation that’s on the line.

The case was tried in the autumn of 2017 by Mr Justice Jay who, as Robert Jay QC, was counsel to the Leveson inquiry into press ethics in 2011/12. The judge had to decide whether Jan Serafin, a Polish businessman who moved to England in 1984, had been libelled by Nowy Czas, a small Polish-language newspaper circulating in London. After a seven-day hearing, Jay dismissed Serafin’s claim.

Serafin argued the case himself: he had not retained a lawyer to question witnesses or make submissions. Unrepresented parties pose particular problems for trial judges hearing cases that involve detailed facts and complex issues of law. One question for the Supreme Court is whether Jay treated Serafin unfairly in court.

That was certainly what the Court of Appeal concluded last year. Allowing Serafin’s appeal, three judges said that Jay had “not only seriously transgressed the core principle that a judge remains neutral during the evidence, but he also acted in a manner which was, at times, manifestly unfair and hostile to the claimant”. The appeal judges concluded that “the nature, tenor and frequency of the judge’s interventions were such as to render this libel trial unfair”.

This is not only damaging to Jay’s reputation, putting on hold the promotion he might otherwise be expecting. It will also have deterred other practitioners from seeking judicial appointment.

But was the criticism justified? Serafin was legally represented at the appeal and his lawyers asked the appeal judges to read extracts from the transcript. “On numerous occasions,” the appeal court concluded, “the judge appears not only to have descended to the arena, cast off the mantle of impartiality and taken up the cudgels of cross-examination, but also to have used language which was threatening, overbearing and, frankly, bullying.”

Not so, argue the magazine’s lawyers in their appeal to the Supreme Court. For the past 20 years, judges have been encouraged to adopt an active style of case management. That requires them to ensure court time is used efficiently. Jay might have been robust, brusque or impatient — but there was no reasonable basis to infer that he either prejudged the issues or prevented Serafin from presenting his case properly.

Needless to say, Serafin’s lawyers side with the Court of Appeal. At the very least, they will tell the Supreme Court, Jay demonstrated an appearance of bias. Ironically, the judge will be given no chance to defend his own judgment.

The issue of unfairness is one that has a bearing on all cases. But the appeal will also consider issues of particular interest to journalists, writers and bloggers.

Section 4 of the Defamation Act 2013 says “it is a defence to an action for defamation for the defendant to show that the statement complained of was … on a matter of public interest and the defendant reasonably believed that publishing the statement … was in the public interest”.

At the trial, the magazine was not able to prove that all the allegations it had made about Serafin were true. So the case turned on whether publication satisfied this public interest test. Jay found that it did — even though Nowy Czas had not approached Serafin for comment before publication.

But the Court of Appeal, drawing on cases decided after the Defamation Act had come into force, said it was a basic requirement of fairness and responsible journalism to give the subject of a story an opportunity to put his or her side of it. Occasions where it was not reasonable to seek a comment would be rare. The newspaper had made no attempt to check or corroborate its story and its “standards of journalism plainly left much to be desired”.

In the Supreme Court, David Price QC for the magazine will argue that the public interest test in section 4 of the Defamation Act is more generous than the judge-made law it replaced. This was known as the “Reynolds” defence after a case decided in 1999 and brought by a former Irish prime minister against The Sunday Times.

Price will argue that the Supreme Court needs to rebalance the test in favour of freedom of expression, as parliament had intended when it passed the 2013 legislation. He is supported by the Media Lawyers Association. Their counsel, Heather Rogers QC, will argue that parliament re-set “the balance between the protection of reputation and freedom of expression, moving the dial slightly more in favour of the latter to protect and promote reporting on matters of public interest”.

In response, Adrienne Page QC, for Serafin, will say that parliament did not intend to go any further than the Reynolds test when it codified the law. It cannot be in the public interest to publish information that the publisher has not tried to verify, she argues, because of the risk it may turn out to be wrong and therefore damaging.

What parliament intended the public interest test to mean may not matter very much. But what the Supreme Court eventually decides that parliament intended it to mean will be of huge importance, not just to writers at every level but to their readers too.