Police guidance on recording hate crimes against transgender people has had a "chilling effect" on freedom of expression, the High Court has heard.
Former police officer Harry Miller is taking legal action against the College of Policing, after he was investigated by police for sharing a poem on Twitter which questioned whether transgender women were biological women.
Humberside Police said the act of retweeting the poem - which featured the words "your vagina goes nowhere" - was a "hate incident" under the College of Policing's guidance on hate crime.
Opening his case in London today, 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, by following the guidance, had sought to "dissuade him [Mr Miller] from expressing himself on such issues in the future", which was "contrary to his fundamental right to freedom of expression".
The ex-police officer had his Twitter account suspended
Mr Wise told the court that Mr Miller had "never expressed hatred towards the transgender community", and had "simply questioned (at times provocatively and using humour) the belief that trans women are women".
Jonathan Auburn, for the College of Policing said that Mr Miller used his Twitter account @HarryTheOwl - which has since been suspended - to engage "in regular tweeting relating to transgender people".
He referred to one tweet in which Mr Miller wrote: "I was assigned mammal at birth, but my orientation is fish. Don't mis-species me. F**kers."
Mr Auburn added: "It is not beyond reason that a transgender person reading those messages would consider them to be 'motivated by a hostility or prejudice against a person who is transgender'".
He argued that the guidance caused no interference with Mr Miller's right to freedom of expression.
Humberside Police are also resisting Mr Miller's case, arguing that there was no, or only a "minimal", interference with his freedom of expression.
The hearing is expected to last for two days.
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