Festival goers have been told to step in if they spot sexual harassment, as new figures show almost half of young women have been attacked.

One in five British festival goers have experienced sexual assault or harassment at an event, according to new research, with 43pc of women under the age of 40 experiencing unwanted attention.

The figures, believed to be the first of their kind, should be a wake-up call for the industry, campaigners said, after a poll showed 22pc of all Britons who have been to a festival faced some kind of unwanted sexual behaviour, rising to almost one in three of all women.

Jen Calleja, a co-director of the Good Night Out Campaign, called the research "shocking but not surprising", saying it "helps prove what we already know through anecdotal evidence.