The Crimes Amendment (Gross Violence Offences) bill will create two new offences of intentionally and recklessly causing serious injury in circumstances of gross violence.

It will require offenders to be jailed with a non-parole period of at least four years but will enable special consideration for offenders who have co-operated with police or suffer from a mental impairment.

Circumstances of gross violence will include violent attacks planned in advance, gang attacks, serious assaults involving weapons, and attacks on victims who are already incapacitated.

Premier Ted Baillieu said the changes would put violent offenders behind bars for longer terms and send a strong message of deterrence to would-be offenders.

But Centre for Non Violence chief executive Margaret Augerinos said laws were never enough of a deterrent.

“We currently have laws about a range of things, but the presence of a law prohibiting certain behaviour, or even prescribing a tough sentence, doesn’t always act as a deterrent,” she said.

“Tougher sentencing does send a strong message to the community about the unacceptability of violent behaviour. However, we also need to put equal effort into preventing such behaviour from occurring.”

Ms Augerinos said tackling family violence, specifically, was more about changing systemic attitudes.

“Not only do we need to ensure police and the courts respond in a timely and appropriate way to family violence offences, we also need to work at changing community attitudes and values that enable family violence to occur in the first place,” she said.

“Consistent messages need to be given to all in society – including perpetrators – that family violence is unacceptable; that the system will respond swiftly to hold the perpetrator to account; that victims will be supported.

“Community education and prevention needs to be implemented at all levels of society – around issues such as gender equality, respectful relationships and the harm that violence does to children and victims.”