Victoria will become the first state to ban fracking after the opposition agreed to support government legislation.
Liberal leader Matthew Guy and Nationals leader Peter Walsh says the bill, which returns for debate on Wednesday, will pass.
Outside parliament on Wednesday, Resources Minister Wade Noonan said the ban would protect Victoria's agriculture sector.
"Farmers have made it absolutely clear to me ... the greatest commodity in regional and rural Victoria, of course, is water, and that's why this fracking ban is so important," he said.
The bill will permanently ban all onshore unconventional gas exploration and development, including hydraulic fracturing, commonly known as fracking, and coal seam gas.
It also extends the moratorium on conventional onshore gas exploration and development to June 30, 2020.
Mr Guy told reporters there was still a need for "a way forward" for offshore conventional gas beyond 2020 to support base load power.
The Victorian coalition's support for the legislation is in conflict with the federal stance, with Prime Minister Malcolm Turnbull and Energy Minister Josh Frydenberg against the ban.
The Resources Legislation Amendment (Fracking Ban) Bill 2016 returns to parliament on Wednesday.
