Victorian police will be given new powers to help them lock up one-punch killers if Labor wins this year’s Victorian election.

A new offence of assault causing death will be created, which the state opposition says will help police in cases where they are unable to secure a murder or manslaughter conviction.

Shadow Attorney-General Martin Pakula said there had been cases in the past where a person had been able to argue their way out of a manslaughter conviction and been acquitted altogether.

“(The police) will still charge with murder or manslaughter, if they are confident they can get a conviction for either of those offences, but in circumstances where they are in doubt, rather than have the risk of someone being acquitted altogether, they will have the option of charging the offender with the assault causing death,” Mr Pakula told reporters.

“We also think it is important to send a powerful message to the community that if you throw a punch and someone dies you will go to jail.

“If even one offender is put off throwing that punch as a result of this law then it has done an important job.”

The offence will carry a maximum penalty of 20 years, the same penalty as manslaughter.

Mr Pakula ruled out a minimum sentence, as is being introduced in New South Wales, saying the party does not support mandatory minimum sentencing.

But he said under Labor policy judges will be required to consult with jurors about an appropriate sentence in cases of serious indictable offences.

The assault causing death offence will be introduced in Labor’s first year of government.

Attorney-General Robert Clark is expected to comment on proposed law at a media conference later on Monday.