Ms Harman is one of the most prominent campaigners leading calls for a change in the law to stop alleged killers and abusers from putting the blame on their victims, dubbed the "Fifty Shades defence".
Supporters are trying to get a new Domestic Abuse Bill through Parliament but an already drawn-out process was held up by the General Election.
They are hoping to get is passed this year.
The former Labour deputy leader has insisted she will not let the issue drop and after Mr Johnson promised to outlaw the defence during the election campaign, vowing to ensure he keeps to his word.
In arguing her case she raised the death of Natalie Connolly, who was left to die in a pool of blood at the bottom of the stairs by her partner John Broadhurst during a drink-and-drugs-fuelled sex session at their home in Kinver in December 2016 in which she was subjected to violent abuse.
The millionaire property developer was jailed for 44 months for her manslaughter and failed in a bid to appeal his sentence last year.
In cases of rape and abuse, and sometimes murder, defendants will often claim that the woman was a willing participant in a violent sexual act and was hurt, or killed, unintentionally.
It can prove a powerful argument in court and has led to the prosecution to back down from a murder charge in favour of manslaughter, believing they will stand a better chance of securing a conviction.
Ms Harman says the practice of placing the blame on female victims needs to stop.
She said: "Men are now getting away with murder, literally, by claiming that though they admit they caused the injuries which led to her death, it was not his fault as it was part of a sex game gone wrong.
"Natalie Connolly, a young woman from the West Midlands, died six months after starting a relationship with millionaire property developer, John Broadhurst.
"He regaled the court with lurid details of the violence which he alleged she consented to.
"When her body was found at the bottom of the stairs, it was not only internal injuries but old bruising on her breasts and buttocks which he says he inflicted at her request.
"Instead of a life sentence for murder, he got only three years, eight months for her manslaughter.
"We want a change in the law to outlaw the rough sex gone wrong defence so that if his actions kill her, he's guilty of murder irrespective of whatever she consented to by way of sex.
"Prime Minister Boris Johnson promised during the General Election campaign that he would outlaw this defence in the forthcoming Domestic Abuse Bill. This is one promise we'll make sure he keeps."