Women who kill their male abusers are often failed by a British justice system that can treat them as cold-blooded murderers rather than seeing them as victims too, campaigners said on Wednesday.

Changes to criminal and legal systems are needed to ensure fairness for women who frequently serve long prison sentences for killing violent or controlling partners, the Centre for Women's Justice and Justice for Women said in a joint report.

New tower illuminated in orange color for International Day for the Elimination of Violence against Women on November 25, 2020 in Kampen, Overijssel, the Netherlands. Photo: VCG

The report reveals "a real lack of understanding and insight into domestic violence" in Britain, said Harriet Wistrich,  director of Centre for Women's Justice.

"If somebody kills because their life is under threat or they have been horrendously abused over many years... that is not the same as someone who coldly plans to kill somebody to benefit," she told the Thomson Reuters Foundation.

"They have acted out of desperation and they are deserving of leniency at the very least."

The Ministry of Justice did not immediately respond to a request for comment.

"We recognize the devastating impact of domestic abuse on victims," said a spokesman for the Crown Prosecution Service, which prosecutes criminal cases in England and Wales. "Prosecutors take all relevant factors into account when deciding the appropriate charge," said the spokesman. 

Nearly 40 percent of female homicide victims were killed by a current or former partner, against just 4 percent of male victims, according to the Office for National Statistics. 

When women do kill their partners, it often follows abuse, said the report.