The prosecution of Dominique Strauss-Kahn is in jeopardy because of "major holes in the credibility" of his accuser. This is a typical defence. A woman who reports rape is expected to have a virginal past to qualify as a credible rape victim. Often more resources are spent investigating the woman than the man she is accusing, especially if he is rich and powerful and she is not. Several women we work with who reported rape have been put under covert surveillance, with hidden cameras and phone tapping, their sex lives scrutinised. Some were accused of being bad mothers, of being either promiscuous or loners looking for attention, of hating men or being desperate to catch one. Most were working class and/or women of colour.

The question, however, is relevance. Kenneth P Thompson, the woman's lawyer, points to forensic medical evidence that supports the woman's account of what happened. He dismisses minor contradictions as the result of hours and hours of exhausting interviews. The best lawyers money can buy say DSK's accuser lied in her immigration application, is a prostitute and is involved in drug-dealing. How is this relevant to her allegation of rape?

They say that she never told the authorities about suffering female genital mutilation in her asylum claim, but has since spoken of it. Some media are suggesting that she may now face deportation.

We see dozens of asylum-seeking women every month who have been raped in their home countries. Women are accused of lying if they didn't tell the authorities every single detail when they first arrive. But many are deeply traumatised. Which of us would confide in a man in authority when we enter a foreign country of which we know little or nothing? Far from embellishing and exaggerating sexual violence, most women applying for asylum minimise it, avoid it, hide it. That is typically what victims do who have suffered rape and other types of torture – they can hardly bear to revisit the pain and the humiliation; some are actually unable to find words to describe what happened to them.

But why is a woman's credibility relevant to a charge when that of the accused is not? Does that mean a rape charge can be dismissed? Other women with much more social power have accused DSK of being a sexual predator, of abusing his position as one of the most powerful men in the financial world and of attempted rape.

So this is what victims of rape face: a criminal justice system where prejudice and politics may shape the investigation and any trial – and even determine the outcome.

This high-profile case first inspired relief among women, particularly among rape survivors, as if a long-buried wound was finally coming to light. One in four women in the UK suffers rape; over 90% of rapes are never reported; and of those reported only 6.7% result in a conviction on a charge of rape. On the SlutWalk march people cheered at the "We are all chambermaids" placards. And at our protest outside the Crown Prosecution Service last Friday, over half a dozen women spoke out about the catalogue of obstruction they had faced when trying to get their rapist prosecuted.

There was a protest of hotel maids in uniform outside the court where DSK appeared in New York, mostly immigrant women of colour. They felt strongly about the allegations because they know well the unwanted advances of the rich and powerful whose toilets they clean.

If the prosecution against DSK is dropped, the age-old myth that women, not men, lie about rape will prevail once more. But women's fury – in New York, in Paris, in London, everywhere – at our inability to get justice on rape, and at the sex, race and class bias of the law, can no longer be repressed.