A Tory MEP has reignited the controversy about degrees of severity in rape, suggesting that some rape victims shared responsibility for the crime.

Writing on his blog, Roger Helmer weighed in behind the justice secretary, Kenneth Clarke, who last week suggested some forms of rape were more serious than others. Helmer's comments were criticised by a party spokesman and by Tory MP Louise Bagshawe, who said his remarks were "appalling".

Helmer described a "classic stranger rape" scenario, where a "masked individual emerges from the bushes, hits his victim over the head with a blunt instrument, drags her into the undergrowth and rapes her, and then leaves her unconscious, careless whether she lives or dies".

He then described "date rape" as being when a woman "voluntarily goes to her boyfriend's apartment, voluntarily goes into the bedroom, voluntarily undresses and gets into bed, perhaps anticipating sex, or naively expecting merely a cuddle.

"But at the last minute she gets cold feet and says 'Stop!' The young man, in the heat of the moment, is unable to restrain himself and carries on.

"In both cases an offence has been committed, and the perpetrators deserve to be convicted and punished.

"But whereas in the first case, I'd again be quite happy to hang the guy, I think that most right-thinking people would expect a much lighter sentence in the second case. Rape is always wrong, but not always equally culpable."

The East Midlands MEP admitted he would be vilified for adding: "While in the first case, the blame is squarely on the perpetrator and does not attach to the victim; in the second case, the victim surely shares a part of the responsibility, if only for establishing reasonable expectations in her boyfriend's mind."

A Conservative spokesman said: "This is clearly not the view of the Conservative party or the UK delegation in the European parliament, and does not reflect the comments made by Ken Clarke."

On Twitter, Bagshawe wrote: "He speaks for himself alone. A woman (or man) always has the right to change their mind. What if their partner insults them (one example)."

Labour frontbencher Caroline Flint branded the comments "outrageous". "To suggest that the victims of date rape can 'share responsibility' for the crime is outrageous. Roger Helmer should apologise immediately," she wrote.