Victorian parliamentarians who fail a random breath test on a sitting day could be docked a day's pay if Labor wins Saturday's election.
MPs and judges would be randomly breath-tested when sitting to make sure their blood-alcohol level was below .05.
"Our parliament is not a pub, it is a workplace," Opposition Leader Daniel Andrews told reporters on Thursday.
Mr Andrews said a bipartisan committee would determine the best way to run the random tests and propose punishments.
"The sorts of sanctions that I think are most appropriate are perhaps docking one day's pay. If it was more significant, it could be a sliding scale," he said.
Mr Andrews refused to say if he'd seen MPs pass laws while drunk, but opposition scrutiny of government spokesman Martin Pakula was more forthcoming.
"I think anyone who's been in parliament for long enough has seen other members who have maybe not been in the best shape when they've been in the House," Mr Pakula told reporters.
The top judges at Victoria's Supreme, County and Magistrates' Court released a joint statement, saying new laws weren't needed to crack down on drinking.
"These types of matters would be well covered by existing mechanisms," the statement said.
Premier Denis Napthine said the plan was an attempt to distract voters from Labor's release of its election policy costings, due on Thursday.
"I personally have no problems with it," Dr Napthine told reporters.
"But it is very hypocritical from Daniel Andrews and the Labor Party, who opposed drug and alcohol testing of workers on construction sites and building sites at the behest of their union masters the CFMEU."
Mr Andrews said he said months ago that if drug and alcohol testing was good enough for building workers, it should be good enough for MPs.
"I support any measure that can improve safety in any workplace across our state, but you can't exempt the parliament as a workplace from that sort of regime," he said.
Mr Andrews would not be drawn on whether MPs and judges would also be tested for drugs, but said the scheme could be expanded in the future.
