A train passenger has become the first person to be sentenced under a new harassment law after a prosecution brought by the British Transport Police (BTP).

David Stroud, 44, grabbed a woman’s hair and asked her “can I kiss you?” on a rail journey to London on 3 April, two days after the new legislation came into force banning harassment motivated by a person’s sex.

The new offence, under section 4B of the Public Order Act 1986, covers intentional harassment directed at someone because of their sex, including where perpetrators target women and girls in public places, including streets, parks and public transport.

Stroud, who admitted he had harassed the woman because of her gender, was “constantly leaning on to the woman” and got closer, telling her “you’re magical” and grabbing her hair which the victim “perceived to be sexual”, Highbury Corner magistrates court previously heard.

He was arrested at London Bridge station after the incident on a train from Hastings, East Sussex, and while under caution he said: “It’s just banter, we had banter together, do you know what I mean?”

Stroud, from Dartford in Kent, was on bail after admitting to a separate 22-month stalking campaign when he harassed the victim on a train. He was given a community order on Tuesday.

Det Supt Sam Painter of the BTP told the Press Association: “We recognise that this offending, in terms of the scale and the nature of it, has been going on for too long.”

As of Monday, 26 men had been arrested for the offence across BTP’s network since it came into effect on 1 April.

Offenders can face up to two years behind bars under the new law, which Painter said “recognises the seriousness of the offending” and the impact it has on women and girls.

Olivia Rose, the Crown Prosecution Service’s lead on stalking and deputy chief crown prosecutor, said the new offence “bridges the gap between where conduct is serious but perhaps doesn’t quite meet the threshold for sexual assault.

“This deals with that, because otherwise we would find that there would be cases that might fall within that gap.”

Stroud had previously pleaded guilty to a separate stalking campaign, the court heard. He stalked his ex-partner’s adult daughter, going to her home regularly and sending her unwanted gifts and over 200 emails.

He was sentenced for both offences together and received a 12-month community order and was told to complete 15 days of rehabilitation activity.

The former technician at a water company was ordered to carry out 150 hours of unpaid work and be fitted with an alcohol abstinence monitoring tag for 90 days.

Judge Jackson also made a five-year restraining order against him for the stalking victim and ordered the defendant to pay £85 court costs and a £114 surcharge.

Speaking to reporters outside court, Stroud said: “The law changes and it is what it is. I was just unlucky that I was the first person at the time.”

He said the victim impact statement made him appear like “a monster”.

“I wasn’t a monster. We had an amicable chat about her iridescent hair.”

He added: “I realised that I’d overstepped the line. And I walked away of my own accord because I thought, right, now it’s time to go.”

Amelia Whitworth, head of policy, campaigns and youth at charity Plan International UK, said: “We spent years tirelessly campaigning alongside dedicated youth activists for this law. The first conviction is an encouraging early sign that it is being implemented and helping to provide some justice for survivors.

“This will go some way to help those affected to feel confident coming forward and able to access support.”