French President Francois Hollande has decided to waive the remaining prison sentence of a woman who murdered her husband of 40 years after suffering decades of physical and sexual abuse. On 10 September 2010 Jacqueline Sauvage shot her husband three times in the back with a rifle, killing him instantly.

Sauvage says it was the culmination of years of abuse at the hands of the violent alcoholic who, she claims, raped and beat her and her daughters on dozens of occasions. The 68-year-old also said that he abused her son – who then took his own life the day before she shot her husband.

During both trials the court heard sickening evidence that Sauvage had been repeatedly beaten and sexually abused by her husband. Her three daughters testified that their father had often raped them too.

Two juries found Sauvage guilty of murder with the appeal court saying that her actions were "disproportionate" because her life was not threatened at the time she seized his hunting rifle. She was sentenced to 10 years in prison in October 2014 after being found guilty of murdering her husband and her appeal failed in December 2015.

Her lawyers had argued that she was acting in self-defence when shooting him dead and more than 400,000 people have signed a petition calling on Hollande to intervene. This led to the unusual step of the Socialist politician meeting Sauvage's daughters last week.

And on 31 January it was announced that she will be able to leave jail in mid-April. Although the release does not quash Sauvage's conviction, it waives the remainder of time she would have spent in jail.

The case became a divisive issue in France with anti-domestic violence campaigners calling for a definition of self-defence to be expanded to include victims of violence. Activist group Osez le Feminisme (Dare To Be Feminist) had called for the definition of "self-defence" for cases of "female victims of violence".

Hollande had distanced himself from such pardons, which were reinstated by Napoleon Bonaparte, describing them as belonging to "a different concept of power" when running foe his 2012 presidency. He has granted just one freeing bank robber Philippe El Shennawy – who had spent 38 years behind bars – in 2014.

"In the face of an exceptional human situation, the president wanted to make it possible for Sauvage to return to her family as soon as possible," the presidency said in a statement.