Paramedics this week argued pills confiscated by authorities at Victorian music festivals should be tested by chemists so revellers can be alerted in real time when dangerous drugs are circulating.

The Victorian Ambulance Union argues change is needed because existing efforts to curb drug use aren't working, with overdoses tying up resources that could be used for other members of the public.

The Greens and the Reason Party tabled a co-sponsored bill in parliament on Wednesday for a two-year pill testing trial.

But Mr Andrews said the Victorian government will continue to oppose the initiative, insisting he is being driven by evidence.

"Even so-called pure versions of these drugs can kill you and we won't be sending a green light for people to use them," he told reporters in Melbourne on Tuesday.

The Liberal opposition is also opposed.

The Greens and the Reason Party both want a dedicated mobile pill testing service for major music festivals and a fixed-site service for more detailed analysis throughout the year.

The City of Melbourne on Tuesday night voted to support a submission backing the proposal.

Reason Party MP Fiona Patten said the legislation is about stopping young people dying and would reduce drug use by promoting education.

The bill is expected to be voted on early next year, giving the parties time to generate support.

But it appears doomed to fail, with the government and opposition collectively holding a clear majority of seats in the chamber.

Greens MP Tim Read insisted the effort is not in vain.

"The big parties say 'No, no, no', then eventually, 'Yes, we thought of it first'," he told reporters on Wednesday.

"This is how pill testing will start in Victoria."

The NSW coroner last week recommended pill testing after a lengthy inquest into MDMA-related deaths at music festivals.

Australian Associated Press