Also known as "intimate terrorism", coercive control is both a predictor of murder and an insidious and private form of violence, which has long-lasting and extremely damaging health and wellbeing consequences.

For decades, survivors have been reporting the most difficult thing about domestic abuse is not necessarily the physical violence, the bruised ribs, chipped teeth or broken bones. The worst part, many survivors say, is the psychological abuse - the manipulation and surveillance, the gradual isolation from friends and family, the rigid rules, degrading put-downs, humiliation and threats - the insidious "system" of behaviours perpetrators use to dominate and entrap their victims known as coercive control.

And yet, this form of violence is not illegal in NSW. It is not a crime. If it was, the deaths of 35 women this year might well have been prevented. As might the significant and long-term psychological emotional injury it causes women and children.

The Coercive Control legislation to be introduced next week into NSW Parliament as a Private Members Bill by our local representative Anna Watson MP, who has tenaciously and compassionately led this initiative, will make coercive control illegal. If successfully passed and appropriately funded, this Bill will save lives. It will prevent lifelong injury and pain to women and children.

Understanding coercive control is not easy. It is defined by sociologist Professor Evan Stark from Rutgers University as a "malign pattern of domination" that can include "emotional abuse, historical abuse, isolation, sexual coercion, financial abuse, cyber-stalking, and other distal forms of intimidation". In other words, it describes a wide range of controlling behaviours that one person (usually a man) commits against another person (usually a woman, and usually a current or former intimate partner). These behaviours collectively strip the other person of their autonomy and sense of self-worth.

Unlike traditionally understood family violence offences, coercive control involves a pattern of behaviour rather than a individual incident.

The United Kingdom and Ireland have introduced legislation making it a crime to engage in what's known as "coercive control" towards an intimate partner. In April 2019 Scotland introduced the ground-breaking Domestic Abuse Act, which creates a "course of conduct" offence allowing physical, psychological and coercive behaviours to be prosecuted at the same time.

Since 2015, tracking of cases in England and Wales where offenders were convicted of controlling or coercive behaviour revealed a range of deplorable behaviours. For example, some offenders threatened to expose private intimate photographs of their partner or ex-partner, prevented their partner from ending the relationship by threatening to, or actually engaging in, self-harm, confiscated or destroyed their partner's mobile phone, deleted all male contacts on their partner's social media, threatened to or actually harmed their partner's pets, demanded that their partner eat or not eat certain foods, demanded their partner sleep on the floor, prohibited their partner from seeking or continuing employment, controlled their partner's finances, with one giving his partner an allowance out of her own income, and conducted regular inspections of their partner's home or body for evidence of infidelity.

The research from the UK also shows that in most cases (but not all), these behaviours occurred in the context of a relationship that typically involved some or all of the following: physical violence, intimidation, degradation, isolation and regulation. While there have been some male victims in these cases, the overwhelming majority were female and the perpetrators came from all works of life and social demographics.

Dr Nithya Reddy, sister of Preethi Reddy, a dentist working in Dapto who was murdered by her former partner, has said that she had never liked her sister's former partner, but did not think he was capable of murder.

"I knew that he had controlling tendencies in other ways - there'd be that coercively controlling behaviour - but it was never threatening, violent or aggressive," Dr Reddy said.

"What I'm realising now is that he had never perpetrated physically violent acts towards her in the past because he knew that he would lose control of her that way.

"So, his first act of physical violence had to be his final act of control."

Domestic and family abuse has received considerable attention in Australia in recent years and yet for all the work that has been done, it is perhaps surprising to note that most of the above behaviours - with the exception of actual or threatened physical violence and stalking - are not criminal. Indeed, these only become criminal if they are a breach of an intervention order.

What does this say to women? What does it say to children when we know especially for children, being in a coercively controlling household can create the same lasting harms as direct physical or sexual abuse?

That such abuse is OK? It is not.

The recent killing of Hannah Clarke and her three children by her estranged husband has raised national attention to the types of behaviour that might lead to such a horrific crime, and how we might spot it early enough to intervene. Evidence is mounting that Hannah's husband had a long history of psychological abuse and controlling behaviours, sometimes called coercive control.

With this knowledge and understanding we have a strong chance of being able to predict these incidents and prevent them. However, we must not forget that not only is coercive control a warning signal for intimate partner homicide, we need it to be illegal in itself.

The Illawarra Women's Health Centre wants coercive control to be a criminal offence in its own right. General manager Sally Stevenson says "Criminalising coercive control is vital, but it must be part of wider reforms to address the current unacceptable reality in Australia, that a current or former partner murders a woman every week, and millions of Australian women experience abuse by an intimate partner at some stage in their lives. Millions."

Over and over again, we see women come into our Centre seeking support for this form of abuse. Client support manager Miranda Batchelor, says "this type of control includes sexual coercion, more bluntly known as rape. Other behaviours include yelling, swearing, name calling, threatening to hurt them/their children/their pets, intimidation (i.e. walking around the house with a weapon, punching the wall near their head), putting them down (making them feel worthless, crazy, hopeless, alone, isolated and ashamed), self-deprivation and financial control, including preventing them from registering with Centrelink for the aged pension.

"These women live in a constant heightened state of fear. When these women find the strength and courage to leave their partners and seek help from the police they are unable to get any sort of protection with being told 'if he hasn't hit you then there's nothing we can do'. These women are survivors and protectors of their children. The system is letting them down."

What we know about cases being prosecuted in the UK gives policymakers confidence the approach can work here, too. Criminalising the seemingly "invisible" behaviours at the heart of so many abusive relationships, we believe would completely reshape the way authorities understand and respond to gendered violence and better hold perpetrators to account.

To honour her, Anna Watson wants her Coercive Control Bill, if passed next week, to become known as Preethi's Law. So, I will leave the last words to Dr Reddy:

"If the systematic set of behaviours aimed at dominating and controlling, which perpetrators such as my sister's ex-partner employ were to have been legislated years before, Preethi may still be here.

"I know that my life for its remaining days will be filled with regret, guilt and what ifs. Some of these are and will be misplaced and some not. And the burden of that cross will become that much more if I don't speak now in earnest to say that I believe one of the biggest factors that could have saved Preethi's life would have been criminalising coercive control.

"If such a bill already existed, she and those around her, including me may very well have recognised the life-threatening dangerousness of the patterns of coercion she experienced for what they were. The reddest of flags. The law can be one of society's most powerful public educational tools and if we were to have a coercive control bill many victims and loved ones may realise, before it's too late, what I am only realising now. So, in Preethi's name, for the goodness, the righteousness and strength she represented, let's pass this Bill before yet one more woman or child is killed."

Survivors are saying, It's about time. The Illawarra Women's Health Centre couldn't agree more.