A woman who fatally stabbed her abusive husband had her murder conviction quashed by the court of appeal today.

Three judges in London substituted a conviction for manslaughter in the case of mother-of-three Donna Tinker, 31, who was jailed for life in April 2000 after a jury found her guilty of the murder of husband, Richard. Her sentence was later set at seven years, which means she is expected to remain in jail for approximately 12 months more.

Tinker, who was present in the dock of the London courtroom as the judges gave their ruling, repeatedly wiped tears from her eyes.

Lawyers on her behalf had urged the court to find the conviction "unsafe".

Lord Justice Kennedy, Mr Justice Sachs and Mrs Justice Hallett were expected to give a ruling later today on the prison sentence she will now have to serve.

Members of Tinker's family embraced each other as the conviction was overturned.

Tinker stabbed her husband with a vegetable knife in June 1999. She said he held his arm around her neck and threatened her with a hot iron in the kitchen of their home in Harrogate, North Yorkshire. The single blow punctured a lung and he died in hospital a week later.

Her defence of provocation was not accepted at her trial, despite evidence of the injuries she had suffered an hour before the stabbing - including a black eye, broken tooth and bruised jaw.

During the appeal hearing earlier this week, Tinker's nine-year-old daughter Natalie - who lives with her two sisters with their maternal grandparents, Alan and Margaret Hall, near Newcastle upon Tyne - gave evidence via video link that she had seen her stepfather with an iron near her mother's face.

The judges quashed the conviction on one ground - that a direction by the trial judge to the jury on the question of lies was "incomplete".

Lord Justice Kennedy said: "We therefore conclude that the direction as to lies was significantly incomplete. The jury did not receive as much assistance as it should have received."

He said that Jeremy Richardson QC, for the crown, "has not sought to persuade us that we should nevertheless regard the conviction as safe, and we consider that in the circumstances of this particular case he was right not to do so.

"Accordingly we allow the appeal to the extent that we set aside the conviction for murder and substitute for it a conviction for manslaughter."

He indicated that the court wanted to see a pre-sentence report and a report from the prison service in relation to the appellant's time in custody.

Earlier in the ruling the judges rejected the evidence of Tinker's daughter Natalie.

Lord Justice Kennedy said: "When she gave evidence before us two days ago, Natalie was, so far as we could tell, all one would expect of a nine-year-old child attempting to assist."

It was necessary to consider whether the evidence "appears to us to be capable of belief". He added: "There are, as it seems to us, a host of reasons for questioning this fresh evidence."

After listing those reasons, the judge concluded: "In our judgment, that catalogue of inconsistencies leads inevitably to the conclusion that although the evidence of a nine-year-old child can be persuasive Natalie's evidence is not capable of belief, and we therefore decline to receive it."

A battered wife serving life imprisonment for killing her husband may soon be freed following evidence from her traumatised daughter which was held back from the original jury.

Donna Tinker stabbed her abusive husband, Richard, in June 1999 with a vegetable knife as he held his arm around her neck and pressed a hot iron against her face in the tiny kitchen of their Yorkshire home. The single blow punctured a lung and he died a week later in hospital.

Despite evidence of the violence that the 32-year-old mother-of-three had suffered - including a black eye, broken tooth and bruised jaw sustained just an hour before the stabbing - her defence of provocation was not accepted in court, ruling out a conviction for the lesser crime of manslaughter. She was found guilty of murder and sentenced to life imprisonment.

Miscarriage of justice and women's groups have been campaigning on Donna's behalf since the verdict two years ago. They point to numerous cases of men being given far more lenient sentences for domestic killings and claim that vital witness statements which backed up Donna's version of events that Sunday evening - including that of the couple's daughter, Natalie - were never revealed at the trial.

Justice for Women, which has taken up Donna's case, hopes an appeal due to be heard on 2 December will overturn the sentence.

'Although very few women kill their violent partners, those who do receive harsh treatment from the legal system, in stark contrast with the sympathy many men are given when charged with killing "nagging" or unfaithful wives,' said Sue Griffiths of Justice for Women.

'Women face great difficulties leaving violent men and regular brutality has a far more serious effect than that of "nagging". No judge has ever asked a man claiming provocation in killing a partner why he did did not leave his wife, yet women are constantly asked this question.'

Since Donna was jailed, she has shared a wing of Durham Prison with notorious murderer Rose West. Donna's parents, Alan and Margaret Hall, have moved to a larger house to devote themselves to bringing up their three granddaughters - Amy, five, Natalie, eight, and Kayleigh, 11 - all of whom have had to have counselling.

Alan Hall told The Observer how his once-vivacious daughter had changed since marrying Richard Tinker. 'She was scared of him and he was certainly a very jealous man. She couldn't go out wearing nice clothes or make-up and she had to keep her eyes down; she daren't look up or he would think she was looking at another man. Once she called her mum after he had hit her and as she was on the phone he walked past and spat in her face.

'Of course we were very worried, but it was only after Richard died that the whole story of what had been happening in that house came out. There wasn't a door that he hadn't punched through. The neighbours told us of the terrible fights.

'After it happened it took a while for Donna to tell us about it - she was in a terrible state. Despite it all, she didn't want to blacken his name.

'His last words were "tell Donna I love her". That's the tragedy - they loved each other; she absolutely loved him. Even in court she held back and only told bits and pieces.

'She was so full of remorse that she couldn't bear to drag his name through the mud. At first she thought he would be coming home - no one would tell her the extent of his injury, and she was defending him to the police because she was still scared of him. 'When it happened he wouldn't let her call the police - she got as far as dialling "99... ", but he stopped her.

'It was only the day his life-support machine was switched off that she told them what had really happened. But the fact she lied to them at first went against her in court, of course.'

The jury had been told she lied to police about Tinker threatening her, because the iron was back in a cupboard. But now a new legal team preparing Donna's appeal has found a statement given to police by a neighbour on the day of the stabbing which stated that they saw the broken iron lying on the kitchen floor, picked it up and put it away. Natalie, then aged five, witnessed what happened that day. She told her counsellors there had been a row between the couple about whether or not Natalie could watch a video, that her mother had been kneeling down ironing the girls' school dresses on top of a towel on the floor when Tinker kicked her viciously in the head.

Later Tinker came up behind her, put his arm around her throat and, picking up the still hot iron, held it to her face. Donna, who is 5ft tall and weighs eight stone, was no match for her 6ft 4in, 16-stone husband. Frantically she grabbed the first thing her hand could reach - a small knife on the kitchen surface - and struck out blindly behind her.

'Donna knows she has to be punished for what she did in a split second of panic,' her father said. 'But life in that prison is no place for a mother who is no danger to anyone and whose children need her. The first day I had to visit my little daughter Donna in prison and heard her screaming behind a glass partition as she was taken back to her cell is one that haunts me.'

In a statement sent to The Observer from jail, Donna said: 'The depth of pain and remorse I feel for my husband dying by my hand is something I am incapable of putting into words. It started as just another argument and moved as it always did to him hitting me. But then he picked up the hot iron and I panicked. I was just trying to stop him hurting me any more.'