A third of Britons believe a woman who acts flirtatiously is partially or completely to blame for being raped, according to a new study.

More than a quarter also believe a woman is at least partly responsible for being raped if she wears sexy or revealing clothing, or is drunk, the study found.

One in five think a woman is partly to blame if it is known she has many sexual partners, while more than a third believe she is responsible to some degree if she has clearly failed to say "no" to the man.

In each of these scenarios a slightly greater proportion of men than women held these views - except when it came to being drunk, when it was equal.

In fact more women (5pc) than men (3pc) thought a woman was "totally responsible" for being raped if she was intoxicated.

Support groups described the findings as "alarming" and "appalling".

The national charity Victim Support urged criminal justice professionals and healthcare workers to "consider how best to educate people about the terrible impact of rape, with a view to changing these attitudes."

The ICM opinion poll, commissioned by Amnesty International, also revealed that the vast majority of the British population has no idea how many women are raped every year in the UK.

Almost all, 96 per cent, of respondents said they either did not know the true extent of rape or thought it was far lower than the true figure.

Only 4 per cent even thought the number of women raped exceeded 10,000. The number of recorded rapes in 2004/5 was more than 12,000 and the 2001 British Crime Survey estimated that just 15 per cent of rapes come to the attention of the police.

'Rape is an appalling crime'

Amnesty International UK director Kate Allen said the poll, part of its Stop Violence Against Women campaign, had uncovered "disturbing attitudes".

She said: "It is shocking that so many people will lay the blame for being raped at the feet of women themselves and the government must launch a new drive to counteract this sexist 'blame culture'."

The research had also exposed the scale of public ignorance over the true extent of rape crimes in the UK and the "dreadfully low" conviction rates, she said.

"The government has an international duty to prevent this gross human rights violation yet it's clear that the government's policies on tackling rape are failing and failing badly," she said.

"These findings should act as a wake-up call to the government to urgently tackle the triple problem of the high incidence of rape, low conviction rates and a sexist blame culture."

Joanna Perry, policy manager at Victim Support, said: "It is alarming to read that so many people seem to believe that a woman is responsible for inviting a rape or sexual assault, because of what she was wearing, what she drank or how she behaved.

"Rape is an appalling crime and has a devastating effect on victims, and those close to them. In other words, nobody asks to be raped."

'Prejudices' in court system

Ruth Hall, from the support group Women Against Rape, criticised "prejudices" in the court system, saying: "They still put the woman on trial, including her sexual history with other men, which is supposed to be banned and blame the woman for what happened to her and hold her accountable.

"If that is the standard set by the people who are supposed to be prosecuting rapists and protecting us it is not surprising if members of the public say the same thing."

She added: "Rather than another Government awareness campaign, the Government's responsibility is to get the criminal justice authorities to prosecute violent men. Let them worry about the awareness of the police, judges and the Crown Prosecution Service and public

awareness will change."

Sheila Coates, director of the South Essex Rape and Incest Crisis Centre, said the poll showed people had little idea about the true extent of rape in the UK.

The support systems for victims were already stretched, she warned.

"The situation for rape victims and women's specialist sexual violence services are at critical," she said.

"Those needing counselling face waiting lists of up to one year and this can only get worse as more rape crisis groups close or cut back services due to a lack of funding and government support. This situation has forced victims into a postcode lottery when trying to find support."

The Home Office said it was determined to increase the number of rape cases which were successfully prosecuted.

A spokesman said: "We have made a number of changes to the legal system and to how the police and Crown Prosecution Service work, to put victims needs first and to make it easier for cases to get to trial and secure convictions.

"We are determined to close the gap between the increasing number of rape cases reported and the low number of convictions."

The number of recorded rapes of a female in 2004-05 was 12,867, up from 12,345 in 2003-04 - an increase of 4 per cent. The number of convictions for rape of a female in 2004 was 741, up from 666 in 2003.

• ICM interviewed a random sample of 1,095 adults aged 18+ by telephone.

They were given a series of scenarios and asked to indicate whether they believed a woman was totally responsible, partially responsible or not at all responsible for being raped.

If the woman was drunk, 4pc said she was totally responsible and 26pc said she was partially responsible.

If the woman behaved in a flirtatious manner, 6pc said she was totally responsible and 28pc said she was partially responsible.

If the woman failed to say "no" clearly to the man, 8pc said she was totally responsible and 29pc said she was partially responsible.

If the woman was wearing sexy or revealing clothing, 6pc said she was totally responsible and 20pc said she was partially responsible.

If it is known that the woman has many sexual partners, 8pc said she was totally responsible and 14pc said she was partially responsible.

If she is alone and walking in a dangerous or deserted area, 5pc said she was totally responsible and 17pc said she was partially responsible.