Campaigners have said figures that show one in five revellers face unwanted sexual behaviour are shocking but not surprising

One in five festival goers have been sexually assaulted or harassed at an event.

A survey has revealed the extent of sexual violence that happens at music festivals in Britain, with campaigners calling for action.

A YouGov poll quizzed a total of 1,188 people who have attended events in the last year, with 22% of respondents saying they had faced unwanted sexual behaviour.

The figure rose to one in three among women (30%) and almost half (43%) of women under 40.

The most common forms of unwanted sexual behaviour experienced were unwelcome and forceful dancing and sexualised verbal harassment.

The research found 70% of those who experienced sexual assault or harassment at a festival said the perpetrator was a stranger. Only 1% of women reported sexual assault or harassment to a member of festival staff, either before or after the event, although 19% of men reported their experience to staff.

Tracey Wise, founder of Safe Gigs For Women, said: “We’ve struggled to find anyone with any definite statistics on this before. It gives us something to show to festival organisers so we can say, ‘you need to take this on board’.”

When people were asked how satisfied they were with how festivals they attended handled the issue, 45% said they did not know and 24% said they were neither satisfied nor dissatisfied, suggesting a lack of awareness around festival policies and safeguards. A total of 22% said they were satisfied and 8% said they were dissatisfied.

Jen Calleja of the Good Night Out Campaign said the findings are shocking but unsurprising.

She said: “We know the vast amount of harassment and sexual assault is not reported and we know this comes down to stigma, fear of not being believed and a minimisation of what harassment is.”

Beth Granter, a 35-year-old campaign manager with social network Care2, said she was flashed by a man at Reading Festival when she was 17.

"He said something like 'give us a shag'," so she said she told him to go away and tried to laugh it off, said Granter.

"Laughing was a defensive strategy to de-escalate the situation," she added.

She said she did not report what happened but felt vulnerable for the rest of the festival.

Paul Reed, chief executive of the Association of Independent Festivals, said festivals have a duty to make their events as safe and enjoyable as possible.

He said: “People shouldn’t feel that they need to tolerate the type of behaviour (at­ ­festivals) that they wouldn’t tolerate in the street.”