More than a quarter of the public say that victims of rape or sex attacks are at least ‘a little bit responsible’ if they were drunk at the time.

Among 16 to 19-year-olds, this leaps to one in three who believe people are partly to blame if they have been drinking. It then falls to fewer than one in four for people over the age of 25.

Research by the Office for National Statistics also revealed that a fifth of victims of sexual assaults were unconscious or asleep. Three out of ten were ‘under the influence’ of alcohol.

One in three teenagers said a rape victim's drunkenness made them 'completely', 'mostly' or 'a little' responsible

The study comes at a time of huge controversy over rape laws in the wake of the Ched Evans case. The Welsh international footballer was released from prison in October, halfway through a five-year sentence for raping a 19-year-old woman.

Jurors had decided that a woman he had sex with was too drunk to consent.

Last month, the row intensified further when the head of the Crown Prosecution Service, Alison Saunders, said society must ‘challenge’ the view that rape victims should be blamed if they had been ‘drinking’.

Footballer Ched Evans was convicted of raping a 19-year-old after a jury found she was too drunk to consent

However yesterday’s ONS report – based on the Crime Survey for England and Wales, which questions thousands of people – found a sizeable minority did think that people who had consumed alcohol before they were attacked should shoulder some responsibility.

Some 6 per cent said the victim is ‘completely/mostly responsible’ if they were drunk. A further 20 per cent said they were ‘a little bit responsible’.

Two-thirds of respondents said the victim was ‘not responsible’ and 7 per cent didn’t know.

Among those aged 25 to 44, around 23 per cent felt that a person who was drunk was at least partly responsible. For those aged 16 to 19, the figure was 33 per cent.

Sarah Green, from the campaign group End Violence Against Women Coalition, said: ‘We already know that a significant minority of the population are inclined to blame women for being raped, but what should be a cause of great concern in these figures is the fact that younger people are more likely to blame women and girls for rape.

‘Young people today are bombarded with confusing messages about men and women and sexuality – women are constantly portrayed as sex objects and it is implied that it is ‘natural’ for men to pursue women to the point of coercion.’

The figures also showed that for over half of victims – 57 per cent – physical force had been used by the offender to try and make them have sex.

One in ten victims reported that the offender had choked or tried to strangle them. A quarter reported that they had been frightened or threatened.

Director of Public Prosecutions Alison Saunders suggested people accused of rape should have to prove how their alleged victim had consented

Overall, sex offences recorded by police rose to 64,205 in 2013/14 – the most since 2002/03 – and the ONS said there was a ‘greater willingness’ to report abuse.

Experts added that the rise in reports was ‘thought to reflect’ better recording.

At a special conference on rape last month, CPS head Mrs Saunders said people accused of sexual crimes must be able to show they had the person’s consent.

‘For too long society has blamed rape victims for confusing the issue of consent – by drinking or dressing provocatively for example,’ she said.