Myths around rape and consent persist in society “with serious consequences for survivors and justice”, the victims’ commissioner has said after a wide-ranging survey of the public.

Almost one in 12 people thought being in a relationship or marriage meant you could always assume the other person had consented to sex, while only half of respondents thought the rules of consent are the same whether online or offline.

Misconceptions also remain around victims and the crime of rape, according to the research commissioned by the Crown Prosecution Service (CPS).

While just under three-quarters (74%) of people overall understood it can still be rape if a victim does not resist or fight back, this fell to a little over half (53%) among 18 to 24-year-olds having this understanding.

A total of 3,066 adults – 50.6% of whom were female – were surveyed across the UK about their understanding of rape and serious sexual offences, and the law on consent.

The CPS said it was the largest survey of its kind in five years and provides the organisation with recent evidence on how the public view rape and serious sexual offences “to further inform our effective handling and prosecution of these cases”.

While the majority of people (54%) thought that if a person said online they wanted to meet up and have sex it did not mean they had to have sex when they met, more than one in 10 (14%) thought the online consent was enough.

Only half of respondents thought the rules of sexual consent applied in every situation and context, whether online or offline.

The End Violence Against Women (EVAW) coalition warned that the “blurring of our online and offline lives has not only created new forms of sexual violence but new ways to blame victims based on our behaviours online”.

While over a third of survey respondents (36%) said that women rarely make up rape allegations, almost a fifth (17%) said women often make up rape allegations, and 41% chose options between these statements.

Baroness Newlove, the victims’ commissioner for England and Wales, said: “This powerful report echoes what survivors tell me: that harmful ‘myths’ and misconceptions persist in our justice system, with serious consequences for survivors and justice.

“These assumptions also play a part in contributing to excessive and unjustified requests for private victim data in rape investigations.

“Yet as this important research underscores, these misconceptions are not set in stone; they can be dismantled over time, and that requires government and justice agencies, like the CPS, to lead the way.

“Victims deserve a system that respects and upholds their rights – and challenges harmful stereotypes.”

These findings will be used to update our training and guidance for prosecutors and advocates, so they are armed with the tools they need to build robust cases focusing on the actions of the suspect, not a victim’s credibility

Andrea Simon, director of EVAW, welcomed the “significant piece of research”.

She said: “While it is encouraging to see some progress in the public’s understanding of consent and the reality of rape, it’s hugely concerning to see how attitudes towards women’s credibility remain deeply rooted across society, with so few correctly identifying that women rarely make up rape allegations.

“We’re particularly worried to see such a stark regression in attitudes among young people compared to older generations.

“The blurring of our online and offline lives has not only created new forms of sexual violence but new ways to blame victims based on our behaviours online.

“It is clear that the rapid, unchecked spread of online misogyny is also driving sympathy for perpetrators and misconceptions about sexual violence among young people. This work is an encouraging start to addressing these harmful attitudes.”

The CPS said it had compared its findings – including stakeholder roundtables and focus groups – to an Amnesty International UK survey in 2005 and found a “slight decline in, or relatively low levels of, rape myth acceptance in England and Wales in recent years” compared with the earlier survey.

But Baljit Ubhey, CPS director of strategy and policy, said that while public understanding of rape has grown over the past 20 years “there is still more to do as a society to dispel prevalent false beliefs about this offending”.

She said: “Our specialist prosecutors know more than most that rape, and its impact on victims, can be commonly misunderstood.

“It is crucial we stay up to date with any evolving misconceptions in the modern digital age so we can provide accurate information and address any harmful assumptions head on as we make our decisions and contextualise these behaviours for a jury.

“We are determined to ensure justice for as many victims of this life-changing crime as possible. These findings will be used to update our training and guidance for prosecutors and advocates, so they are armed with the tools they need to build robust cases focusing on the actions of the suspect, not a victim’s credibility.”

– Survation carried out the survey and 91% of respondents were from England and Wales.