A woman jailed for "falsely retracting" allegations that she had been raped six times by her husband will today lodge an appeal against her eight-month prison sentence.

There was outcry last Friday when the 28-year-old was sent to jail for perverting the course of justice after she decided to withdraw the rape allegations - not, she said, because they were false, but because her estranged husband and his sister had "'emotionally blackmailed" her into doing so.

Campaigners have called for her immediate release, saying the prosecution, which is believed to be a legal first, sent out a "chilling message" to rape victims and ignored the pressures placed on abused women by the perpetrators of such crimes.

The woman's solicitor told the Guardian today her legal representatives were preparing an appeal application against her sentence. They are also applying for her to be released on bail from Styal prison, where she is being held pending the appeal. Though unusual, it is possible for a judge to grant bail to convicted prisoners waiting for their appeal hearings.

Holly Dustin, director of the End Violence Against Women Coalition, said: "Imprisoning a woman for a 'false retraction' of a rape allegation sends out a chilling message that the criminal justice system is still in the dark ages in relation to sexual violence and does not understand the pressure women come under from perpetrators during the legal process."

She added that the move could make victims less likely to report rape to police if they felt they could themselves be dragged before the courts and face a jail sentence if they did not proceed with the allegations.

Edina Williams, who helps victims of rape, said: "I find it astonishing that in this day and age this woman was hauled before the courts. She is the victim of repeated rapes but she is the one behind bars. It simply does not make sense.

"Many women are victims of domestic rape and, as well as being a terrifying time for them, it is often confusing. Instead of punishing women by throwing them in jail, victims should be given specialist support, counselling and assistance from agencies including the police."

The woman, from Powys, dialled 999 last November and told officers she had been raped six times by her husband. Police charged him with rape.

In January, however, as the case against her husband proceeded, she told officers she wanted to drop the charges, even though she still maintained they were true.

In February, she said she had lied about the rape claims, and they were untrue. Officers from Dyfed-Powys police then arrested her and she was charged with perverting the course of justice. In July, the woman changed her mind once again, saying the rapes had actually happened.

Her solicitor said she had lied earlier because she was being "emotionally blackmailed" by her significantly older husband during the breakdown of their marriage, which was now over.

She told officers she had been persuaded by her husband and his family to drop the charges because he could face a long jail sentence if convicted of rape, while she would get only a few months.

On Friday, furious relatives of the woman shouted at Judge John Rogers QC as he jailed her at Mold crown court.

The judge said the woman had changed her position again after being told she would be prosecuted for a false allegation of rape, which could have carried a longer sentence, of up to two years. He told her: "When you were informed you were to be prosecuted for a false allegation of rape, you went back on your original position.

"You now have to be dealt with for making a false retraction. If you had to be dealt with for making a false allegation of rape you would be looking at a sentence of two years."

He said she had wasted a "substantial amount" of time and money for the Crown Prosecution Service and the police. The husband, who appeared in court at an earlier hearing, pleaded not guilty to rape.

The case is not the first to see a woman jailed following allegations of falsley reporting rape. In June 22-year old Leyla Ibrahim, from Carlisle, was found to have fabricated an incident in which she said she was attacked by two youths whilst walking home late at night, despite medical evidence including a head injury which one expert said it was "unlikely" could have been self-inflicted.

Ibrahim, who was seven months pregnant at the time of her conviction, was sentenced to eighteen months in jail after a judge described her conduct as "wicked".

However the Crown Prosecution Service defended its decision to prosecute the latest case of false rape allegations, stating: "We are acutely aware of the difficulties faced by victims in reporting rape and work hard to support complainants in giving their best evidence at trial. This case was extremely unusual in that the complainant actively worked to derail the trial, by telling police she had made up her original evidence, after initially withdrawing her support for the case.

"In these exceptional circumstances it was felt that the difficult decision to charge the complainant with perverting the course of justice was justified, particularly as substantial resources were used to investigate and prosecute the alleged rape and to provide support to the complainant."

• This article was amended on Friday 26 November 2010. We have amended factual detail.