Just one in seven British rape victims believe they will get justice if they go to the police, according to a survey published on Tuesday that the victims' commissioner said showed a need for radical change.

The survey of nearly 500 survivors came after official data showed prosecutions and convictions for rape fell to a record low in England and Wales last year, amid criticism of the state prosecution service.

"We already knew the number of rape complaints resulting in a charge was at a record low," said Vera Baird, victims' commissioner for England and Wales, in a statement.

"It should therefore come as no surprise to find that only around one in seven rape survivors tell us they have any hope of receiving justice. This survey and the voices behind it reveal the extent of the crisis within our justice system." The number of rape prosecutions fell by about 30% year on year to 2,102 in 2019/20, while convictions were down 25%, according to the Crown Prosecution Service (CPS).

Baird has attributed this to a policy of only prosecuting rape cases that were "rock-solid".

The CPS said it was reviewing the response to rape in consultation with Baird and with survivors' groups as well as recruiting more police and extra advisers to support rape survivors.

Victims "deserve to know that their cases will be taken seriously and pursued rigorously through the courts", it said in an email.

On Monday the CPS published new legal guidance on dealing with digital material like naked selfies and explicit videos, saying this was now "a part of everyday life" for many young people.

Baird said the proportion of victims withdrawing their support for their case had grown, and the survey showed many felt their credibility was being tested.

Rape crisis centres said this chimed with their experience.

"Fear of not being believed is absolutely a big contributing factor to not wanting to put themselves through the criminal justice process," said Katie Russell, a spokeswoman for the charity Rape Crisis England & Wales. "There's also awareness that process can take a very long time – two years was not uncommon before COVID-19 and now with the courts' backlog and everything else the criminal justice process is even longer," she told the Thomson Reuters Foundation.

The survey results are based on responses from nearly 500 rape victims to a questionnaire on a government website in June and July 2020.

Ellie Butt, head of policy and public affairs at the British charity Refuge, said it should strike "serious alarm bells".

"It's clear that much more needs to be done to make the system work for survivors and in turn build their confidence in the system," she said.