Humberside Police unlawfully interfered with a man’s right to freedom of expression by turning up at his place of work over his allegedly “transphobic” tweets, the High Court has ruled.

Former police officer Harry Miller, 54, who founded the campaign group Fair Cop, said the police’s actions had a “substantial chilling effect” on his right to free speech.

Mr Miller, who is from Lincolnshire, claims an officer told him that he had not committed a crime, but that his tweeting was being recorded as a “hate incident”.

The College of Policing’s guidance defines a hate incident as “any non-crime incident which is perceived, by the victim or any other person, to be motivated by a hostility or prejudice against a person who is transgender or perceived to be transgender”.

In a ruling on Friday, the High Court in London found Humberside Police’s actions were a “disproportionate interference” with Mr Miller’s right to freedom of expression.

But Mr Justice Julian Knowles rejected a wider challenge to the lawfulness of the College of Police guidance, ruling that it “serves legitimate purposes and is not disproportionate”.

The judge said: “The claimants’ tweets were lawful and there was not the slightest risk that he would commit a criminal offence by continuing to tweet.

“I find the combination of the police visiting the claimant’s place of work, and their subsequent statements in relation to the possibility of prosecution, were a disproportionate interference with the claimant’s right to freedom of expression because of their potential chilling effect.”

At a hearing in November, Mr Miller’s barrister Ian Wise QC said his client was “deeply concerned” about proposed reforms to the law on gender recognition and had used Twitter to “engage in debate about transgender issues”.

He argued that Humberside Police, following the College of Policing’s guidance, had sought to “dissuade him (Mr Miller) from expressing himself on such issues in the future”, which he said was “contrary to his fundamental right to freedom of expression”.

The judge said Mr Miller strongly denies being prejudiced against transgender people, and regards himself as taking part in the “ongoing debate” about reform of the Gender Recognition Act 2004, which the Government consulted on in 2018.