The decision by a court not to increase the sentence of a man who strangled a woman during sex has been described as the "ultimate victim-blaming".
Sophie Moss died after Sam Pybus applied pressure to her neck when they had sex at her home in Darlington in the early hours of 7 February.
His original four-year, eight-month sentence for manslaughter was referred to the Court of Appeal, which on Friday declined to increase the term he should serve in jail, instead finding the decision of the lower court was not "unduly lenient".
Labour's Harriet Harman, who had written to Attorney General Suella Braverman to complain about the initial sentence, said the ruling was "not justice and it's not justice for Sophie and it's not Pybus being held accountable".
Ms Harman, the chair of the parliamentary joint committee on human rights, added: "And this confirms why we must have a new law to make sure that men who claim rough-sex-gone-wrong defence are prosecuted for sex murder with a mandatory life sentence.
"This is the ultimate victim blaming and it's the ultimate male excuse for domestic violence."
The Centre for Women's Justice said the decision by the court suggested Sophie was "partly culpable for her own death".
The case has been highlighted as the latest in a series of examples when a "rough-sex defence" has been used by men accused of killing women.
Harriet Harmen, who has campaigned on the issue, told the Commons in 2019 that men "are literally getting away with murder by using the rough-sex defence".
Lawyers representing the Attorney General's Office had argued that Pybus should serve a longer sentence and asked three judges at the Court of Appeal to consider the case.
Pybus, now aged 32, was drunk when he applied pressure to Ms Moss' neck for tens of seconds or even minutes at her flat in Darlington, County Durham, in February, Teeside Crown Court heard.
He woke up and found Ms Moss naked and unresponsive but did not dial 999, waiting in his car for 15 minutes before driving to a police station to raise the alarm, the court heard.
A post-mortem revealed he had applied enough pressure to her neck for long enough to kill. There was no evidence of any other injuries or violence.
The Crown Prosecution Service said there was not sufficient evidence to support a charge of murder as there was nothing to suggest he intended to kill her or cause serious harm.
Pybus, of Middleton St George, Darlington, told police he and Ms Moss had been in a casual relationship for three years, and that she encouraged him to strangle her during consensual sex.
The court heard that Ms Moss's long-term partner, who has not been named, said something similar.
Ms Braverman said on Friday she was "disappointed" by the Court of Appeal's decision.
The Centre for Women's Justice said the Pybus case illustrates "a complete lack of understanding of the nature of violent male offending".
Director Harriet Wilstrich said: "Unfortunately the attorney general was bound to accept the case as presented by the prosecutor in the lower court, and in particular that Sophie Moss 'enjoyed asphyxiation'.
"This is a form of victim-blaming, suggesting that she was partly responsible for her own death."
The court's decision has also been criticised by Pybus' ex-wife, Louise Hewitt, who said it shows the "rough-sex defence is valid and works, even though the Domestic Abuse Act was supposed to abolish it".
The Domestic Abuse Act, which came into force in April, features a section that says a person cannot consent to the infliction of serious harm, or by extension, their own death, for the purposes of obtaining sexual gratification.
It was designed to ensure that if a defendant claims a victim's death, or the injuries they sustained, was the result of "rough sex gone wrong", they would remain liable to prosecution for a relevant offence.
Ms Hewitt said the sentence her ex-husband received "doesn't reflect the lifetime of grief that has been inflicted on Sophie's family, especially her two sons who have to grow up with that narrative about their mum".
She said: "I think it was a very lenient sentence and it places the responsibility on Sophie, which to me is victim-blaming and that should not be allowed to happen."