The survey found there was some reluctance to report being raped
A majority of women believe some rape victims should take responsibility for what happened, a survey suggests.
Almost three quarters of the women who believed this said if a victim got into bed with the assailant before an attack they should accept some responsibility.
One-third blamed victims who had dressed provocatively or gone back to the attacker's house for a drink.
The survey of more than 1,000 people in London marked the 10th anniversary of the Haven service for rape victims.
More than half of those of both sexes questioned said there were some circumstances when a rape victim should accept responsibility for an attack.
The study found that women were less forgiving of the victim than men.
Of the women who believed some victims should take responsibility, 71% thought a person should accept responsibility when getting into bed with someone, compared with 57% of men.
Elizabeth Harrison from Haven said there was never an excuse for forcing a woman to do something she did not want to.
"Clearly, women are in a position where they need to take responsibility for themselves - but whatever you wear and whatever you do does not give somebody else the right to rape you.
"It's important people take the time to actually look at what they are doing and make sure the person they are with is actually wanting to go ahead with what they are proposing."
The survey also found more than one in 10 people were unsure whether they would report being raped to the police, and 2% said they would definitely not do so.
The main reasons were being too embarrassed or ashamed (55%), wanting to forget it had happened (41%) and not wanting to go to court (38%).
Meanwhile, the survey suggested that many people are relaxed about their safety. Almost half of people have walked home via side streets on their own.
One in five has been so drunk they have lost their memory, while one in five has got into a taxi without checking whether it is licensed.
When asked about their own experiences, more than a third of those polled said they had been in a situation where they could have been made to have sex against their will.
Women are more likely to have been in this situation - 40% compared to 20%.
And one in five adults had been in a situation where they were made to have sex when they did not want to. This had happened to more women (23%) than men (20%).
The online survey, titled Wake Up To Rape, polled 1,061 people aged 18 to 50, comprising 712 women and 349 men.
An Amnesty International report five years ago found that a significant minority of British people laid the blame for rape at victims themselves.
BBC home affairs correspondent Danny Shaw says this latest study suggests attitudes may have hardened. And the findings may help explain why juries are reluctant to convict in some rape trials.
Amnesty International's UK director Kate Allen said the new findings were "alarming but sadly not surprising".
"It is depressing that, nearly half a decade later, people are still quick to blame the victim of rape rather than placing the responsibility where it actually belongs - squarely on the shoulders of the perpetrator," she said.
"The government has announced that it will develop an 'integrated strategy' to tackle violence against women and these findings are another reminder of how urgent this is and how proper training, support and resourcing will be vital in making it a reality."
The Home Office said it had introduced a number of measures to the service provided to rape victims, including new police and prosecutors' guidance, monitoring of services and funding for support for rape victims.
A spokeswoman said: "The government is determined to ensure that every victim has immediate access to the services and support they need so that more victims have the confidence to come forward and report these crimes and we can bring the perpetrators to justice."