Victoria will move closer to a permanent ban of fracking under a re-elected Labor government.

The controversial process of exposing oil and gas sources by injecting high-pressure liquid into the onshore earth is already outlawed in Victoria, but Premier Daniel Andrews wants the prohibition added to the state's constitution.

The move means it would be harder to reverse the ban in future.

"We'll put beyond the reach of some in politics and their drilling mates, we'll put it beyond their reach to start smashing up our wine country, our dairy country, our tourism assets in order to secure corporate profits," he told reporters at the regional town of Moriac, west of Melbourne, on Friday.

"These assets are precious and we should do everything we can to safeguard them."

Labor would also put $1 million towards marketing and promoting the ban and its benefits for the state's food and fibre sector.

The constitutional ban would not include conventional onshore gas drilling, which would remain under moratorium until 2020.

The change would still have to pass parliament and but would mean reversal "would need to be almost universally accepted before you'd be able to change it", Mr Andrews added.

Regardless of the outcome of the November 24 poll in the upper house, Mr Andrews said he would expect the chamber to respect the government's mandate and permit the changes.

The government has previously been criticised by the other side of politics over the stay on onshore exploration, at times being blamed for creating high gas prices.

Labor spent Friday focused on nature, with the premier and Environment Minister Lily D'Ambrosio making the journey to the Great Otway National Park to announce half-price camping fees.

Labor already scrapped camping fees at 500 basic camp sites in 19 parks while in government and is promising to make the remainder half price if re-elected - a saving of about $20 to $40 a night.

It's also promising to spend $105.6 million over four years on creating more camp grounds and improving four-wheel-drive and walking tracks.

The cash includes $1.5 million to plan a sea-to-summit hiking trail in East Gippsland and $11.6 million for local councils to help maintain and re-vegetate campsites.