The Victorian Labor Party will seek to legalise medical cannabis if it wins the state election in November.

The drug would be made available to treat people with terminal illnesses or life-threatening conditions.

Opposition Leader Daniel Andrews said the law is outdated and "needs to be modernised".

Mr Andrews will ask the Law Reform Commission to advise on how to prescribe and regulate the drug with the aim of presenting a bill to Parliament by the end of 2015.

Mr Andrews said the evidence is clear that there are benefits from using medical cannabis.

"I've spoken to many families with children who suffer forms of epilepsy, for instance, who have gone from having hundreds of seizures every day, to – once they've taken a liquid form of medical cannabis, a drop under the tongue – now suffer no seizures at all," he said.

"You've got parents, and I've met some of them, who are put in this terrible position where they can do the right thing by their child, or they can obey the law.

"That's not a choice that any parent should have to make."

Mr Andrews said the use of the drug would be strictly regulated.

"This is not about smoking anything. This is not about illicit drugs or recreational drugs. This is not about wrecking lives," he said.

"It's about saving lives and the time has come to modernise the law.

"Medical cannabis will be legalised and regulated for those patients who suffer a life-threatening condition, for those patients who are terminally ill."

Medical cannabis a 'no brainer' for O'Connell family

Cheri O'Connell's daughter Tara has a severe form of epilepsy.

She has gone from having 65 seizures on a good day to having no seizures for 17 months since she started using the cannabis treatment.

Cherie O'Connell (left) supports Daniel Andrews' push to legalise the use of medical cannabis. ( ABC News: Catherine Grau )

"Every day we give a dose and we don't know if someone's going to come knocking," Ms O'Connell said.

"For us it's a relief, it's the knowledge that we can go on saving Tara's life and not having the threat of DHS or the police knocking on our doors."

Ms O'Connell said since using the drug, Tara's health has been fantastic.

"For us it was a no-brainer. We'd been told Tara probably wouldn't survive another resuscitation," she said.

"Time was running out for her. We needed to do something quickly and we didn't have time to wait for legislation to change."

AMA Victoria president Dr Tony Bartone has backed the move.

"We know there's a growing body of evidence that cannabis is an effective treatment in conditions such as chronic pain management, muscle spasticity [and] also as an appetite stimulant in certain conditions," he said.

"We know it's being used in a number of other countries around the world.

"We welcome this announcement because it would allow clinical trials to occur in Victoria without the confusion or the issues around these laws on its use."