The number of alleged sexual assaults committed by taxi or minicab drivers has risen by 20 per cent in three years, figures show.
At least 337 assaults were reported between April 2016 and March 2017 in England and Wales – up from 282 in 2014-15.
The figures, obtained by The Guardian using Freedom of Information requests from 23 out of 43 police forces across the country, also included several incidents when the alleged victim was under 16.
The number relates to different types of private hire and taxi services including minicabs, Uber cars and black cabs.
Campaigners have said the rise could be due to more women coming forward to report sexual assault. They also blamed a lack of vigilance on behalf of minicab firms and ride-hailing apps when it comes to checking drivers.
Katie Russell, a spokeswoman for Rape Crisis England and Wales, said: "It’s an alarming figure but it is always hard to know whether the increase is due to a rise in crime taking place or an increase in sexual assaults being reported.
"Sexual offences have been massively underreported so an increase in willingness to report will play some part in the statistical increases.
"The obvious next step is for companies themselves to do urgent reviews of their security systems because obviously there are some weaknesses.
"We know rapists and sexual offenders are often quite devious in how they plan their attacks. They often get themselves in positions of authority and responsibility, where they have access to potential victims - those industries may be attractive to sexual offenders."
The news comes after Uber was stripped of its licence to operate in London after Transport for London (Tfl) raised multiple concerns about its business practices, citing a "lack of corporate responsibility” in relation to driver background checks and reporting serious criminal offences.
Uber is currently pursuing an appeal against Tfl's decision, which is due to be heard by the courts in spring next year. Meanwhile, it has also been banned from operating in York.
The majority of the reports of sexual assault were in London, which is home to 39 per cent of all licensed taxis or private hire vehicles, with the number reported rising from 142 to 156 since 2014-15.
Det Supt Adnan Qureshi, of the Metropolitan Police’s roads and transport policing command, said: “The Metropolitan Police Service (MPS) will not tolerate any offences committed upon passengers of private hire vehicles and will robustly pursue offenders. Any offence is one offence too many.”