The leader of a universities union has agreed to pay “substantial damages” to a firefighter over tweets he claims falsely portrayed him as “a misogynist, a pervert and a liar”, the High Court has been told.

Paul Embery, a trade union activist, launched a libel claim against Dr Jo Grady, general secretary of the University and College Union (UCU), over her response to him highlighting the anti-social behaviour of a group of train passengers on Twitter.

At a hearing in London on Tuesday, Judge Jaron Lewis was told that Mr Embery was “prepared to let the matter rest” after Dr Grady agreed to pay damages, legal costs and not to repeat her allegations.

Speaking to journalists afterwards, Mr Embery claimed he would receive just under £10,000 in damages, with Dr Grady having to pay over £12,000 in costs.

Tom Double, representing Mr Embery, told the court that the firefighter had been travelling with his children from London to Norwich in August 2022 where “a group of women sitting directly behind them were consuming alcohol and behaving in a loud and obnoxious manner”.

“One woman in particular was repeatedly using sexually explicit profanities. Mr Embery considered it unacceptable that passengers, including his own children, should be subjected to this behaviour, so eventually he intervened and politely asked the women to refrain from swearing,” Mr Double said.

His request was met with “hostility and abuse” and, despite a train guard intervening, their “loutish” behaviour continued, which included Mr Embery being warned he would be “knocked out” and being threatened with a beer bottle, the court heard.

Mr Embery filmed the group on his phone, and tweeted a photo of them to train operator Greater Anglia in the hope it would “take action” against the women.

The tweet “went viral” and was seen by over a million people, Mr Double said.

Over the next two days, Dr Grady published tweets, with one saying: “Grow up Paul and take a day off bullying women and pretending to be outraged for clicks. It’s pathetic at any age, but especially yours.”

She also tweeted: “It’s creepy to record young women on the train, share that video, and lie about them on social media for clout.”

Mr Double claimed the tweets from the “highly influential figure” had accused Mr Embery of “being a serial harasser of women and lying about the incident in question”.

The lawyer said they were retweeted and “liked” thousands of times causing “immeasurable harm” to the firefighter’s reputation.

“They portrayed him as a misogynist, a pervert and a liar, when all he was doing was seeking to defend himself, his children and fellow passengers from rowdy and threatening behaviour on public transport,” Mr Double said.

“They contained wild and reckless allegations; all entirely without foundation.

“Mr Embery has always been a vocal public supporter of women’s rights and deplores all bullying and violence towards women and girls.”

Mr Double said Dr Grady’s allegations caused “considerable distress”, adding that Mr Embery had given an “honest” account of the train incident, did not share the video on social media and had been solely motivated to report anti-social behaviour.

“His tweet highlighted a very real problem that ordinary, decent passengers face every day on public transport,” the court heard.

Dr Grady refused to apologise and withdraw her allegations after Mr Embery wrote to her, the judge was told, with the firefighter subsequently pursuing legal action.

“Dr Grady has now agreed to pay Mr Embery substantial damages and legal costs. She has additionally undertaken not to repeat the allegations or similar allegations,” Mr Double said.

After the short hearing, Mr Embery told reporters that he would donate all his damages to charities “campaigning to defend women’s sex-based rights and defend the integrity of women’s sports”.