A ticket inspector helped two young girls escape the unwanted attention of an older man while on the train home to Hitchin.
James, 28, was checking passenger tickets when he noticed an older man staring intently at the teenage girls.
The two girls, aged 15 and 16, had travelled to London for a dance class and were returning home when the incident took place.
While on a train from Kings Cross to Hitchin, an older man, leant on his forearm and focused his stare in their direction, making them uncomfortable.
According to Gemma Reboul, the mother of one the teenagers, James felt "uncomfortable" seeing the situation and did not hesitate to move them to a safer area.
She said: "When he tried to move them, the man tried to follow them. James then said 'you don't need to go anywhere'.
"He escorted them down to first class and I think he waited with them until they got to Hitchin and made sure they were safe."
Gemma posted the incident on a Facebook group to hopefully find James and send her thanks.
She added: "I hope he does get some sort of recognition because he does deserve it. So many people don't get involved because they're too scared or embarrassed and he did."
James' manager Gary Chapman has praised him for his efforts to keep the young girls safe.
Speaking about James, he said: "He's very conscientious and always very aware of what's going on around him.
"The fact that he saw what was happening and took firm and decisive action and then stopped the man from following the two girls was terrific."
Chapman spoke with James shortly after the incident to check his wellbeing and praised him for his customer service.
He added: "It's so rewarding to see the public response, which I've passed on".
This comes after a new campaign to crack down on inappropriate behaviour on the London Underground was launched last month.
The campaign by Transport for London aims to tackle the sexual harassment women and girls face on the tube including 'intrusive staring of a sexual nature'.
Should anyone 'see it or experience it' they should text British Transport Police on 61016 or in an emergency, call 999.
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