Matt Hancock took his fight with former Tory colleague Andrew Bridgen back to court on Tuesday as the Court of Appeal heard his challenge to a libel claim over a January 2023 post on X.

The dispute began on January 11, 2023, after Bridgen shared a story by a controversial scientist who claimed the Covid vaccine could be the worst crime against humanity since the Holocaust. Bridgen lost the Conservative whip after the tweet and was later expelled from the party. On the same day, Hancock posted a video of himself asking a question in the House of Commons and described the comments as “the disgusting and dangerous antisemitic, anti-vax, anti-scientific conspiracy theories spouted by a sitting MP this morning” that were “unacceptable and have absolutely no place in our society.”

Bridgen is suing Hancock for libel over that post, and a High Court judge ruled in April last year that the claim could go to trial after refusing Hancock’s bid to end it. Hancock has since challenged that decision at the Court of Appeal, arguing through his barrister, Aidan Eardley KC, that the case should not have been allowed to proceed. Eardley told the court that Hancock’s position is that the opinion he is being sued for expressing is his honest opinion, adding that “this is a libel claim that should never have been brought” and that it concerns political speech “well within the generous limits afforded by the defence of honest opinion.”

Bridgen’s lawyer, Christopher Newman, took the opposite view. He said the tweet is “not, on its face, antisemitic given the use of the word ‘since’ and all known definitions of antisemitism,” and argued that Hancock was trying to avoid a conclusion that could be fatal to his defence. Newman also said Hancock was “simply wrong” to suggest there is considerable uncertainty over what antisemitism means because of the existence of several definitions.

The panel hearing the case — Lady Justice King, Lord Justice Warby and Lady Justice Whipple — will give its ruling in writing at a later date. The appeal leaves Hancock still trying to stop a trial in a dispute that links a single social media post to the fallout from one of Westminster’s most combustible rows, while a public inquiry continues in the background.