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, six months after New South Wales introduced tougher penalties.

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 also applicable for 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.”

“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.”

The changes follow the deaths of a number of Victorians over recent years, including Shannon McCormack, 22, who died in 2007 after being punched at the Queensbridge Hotel in Melbourne.

Canadian tourist Cain Aguiar, 26, died when he was punched and hit his head outside a hotel at Yarraville in 2009.

The move follows the introduction in January of laws in NSW which include mandatory eight-year prison terms for anyone who fatally punches someone while under the influence of drugs or alcohol.

NSW also toughened penalties for steroid possession, boosted on-the-spot fines for drunken behaviour from $200 to $1100 and imposed a lockout on Kings Cross bars.

During the debate over the NSW laws, then-Premier Barry O’Farrell said that action was needed because the courts had not been prepared to hand out the sentences that people expect.

“It has to be to address an issue that, if the status quo was to remain, would continue to see too many innocent victims either killed or seriously injured.

“If we have to come back and revisit this, if we have to fine tune, we will because we are determined to put in place an effective regime.”

Introducing the Victorian laws, Attorney-general Robert Clark said offenders who committed one-punch crimes currently attracted 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.”

Noel McNamara, from the Crime Victims Support Association, welcomed the Victorian move, calling it a step in the right direction to get rid of the “coward punch”.

He said smart lawyers had been blaming such deaths not on the punch, but rather on the impact from the punch, and he was glad that had been taken out of the equation.

“It’s certainly going to be a lot better than what it’s been,” he said.

“They’ve just been virtually walking away and saying they hit the concrete and that’s what killed them not the punch.

“But the punch shouldn’t have been thrown in the first place.”

ABC, AAP