Amir Marzouq, 22, has today been told he will serve four years in prison, and will be banned from rail travel for life.

The repeat sexual offender was found guilty of groping at least nine young women on the tube network on Central, Bakerloo, Victoria and Northern line trains between December 2010 and September last year. The court heard how one victim was just 15-years-old when she was 'fondled' by Marzouq on August 19 2011, on her train towards Piccadilly Circus.

Last week a YouGov survey revealed that 4 in 10 women in the capital had been sexually harassed in public places, including public transport. Holly Dustin, director of Evaw, has said that ‘Dismissing sexual harassment – from unwanted comments on the street about appearance to groping – as "harmless fun" or complimentary was dangerous’.

Judge Martyn Zeidman told Marzouq: 'You conducted what can only be described as a sustained campaign of sexual abuse.'

The conviction and lifetime ban from rail services that was issued today marks a positive move, and a warning that sexual harassment and assault is illegal and proceedings can be brought against the perpetrators.