Coward punch killers targeted in Vic

Thugs who kill people with a single blow, or a "coward punch", will face a decade behind bars under new sentencing laws to be introduced in Victoria.

The Victorian government hopes the minimum ten-year sentence will flash through the minds of anyone considering throwing a punch.

The crackdown will also hit with the mandatory ten-year jail term anyone convicted of manslaughter in a gang attack.

Premier Denis Napthine said the laws were designed to deter people committing the "unspeakable acts of cowardice."

"There is no place for violence in our community, on our streets, in our pubs and nightclubs. There is no place for violence on our sporting fields or in our homes," Dr Napthine said.

"Too many Victorians, particularly young Victorians, have died as a result of these coward punch killers."

"This is about sending a clear message that one punch can kill. People should step back and think before they throw a punch."

Unveiling the laws alongside Dr Napthine on Sunday, Attorney-General Robert Clark said offenders who commit one-punch crimes currently attract sentences of around five years.

"So this is a very substantial strengthening of the penalty," he said.

Mr Clark said Caterina Politi, the mother of David Cassai who was killed with a blow in Rye in the early hours of New Year's Eve in 2012, was among the people he spoke to before announcing the laws.

"What she had to say was very striking, very persuasive, very informative about the horrific circumstances people can face on our streets these days and the importance of sending a very clear and strong message."

The proposed law change comes after the NSW government passed eight-year minimum mandatory sentencing laws in January for fatal one-punch assaults if alcohol or drugs are involved.

Dr Napthine does not expect the proposed law to increase the strain on Victoria's crowded jail system, saying it is designed to act as a deterrent.

"Our expectation is that this legislation sends such a strong message that we don't have people doing these cowards punches in the first place."

The government will introduce the law into parliament this week and expects it to be passed before this year's election.