The Greens and marine conservationists accuse the government of plotting to use an inquiry into water quality on the Great Barrier Reef to try and discredit Queensland's laws to protect the reef.

"This government is at war with science and the reef will suffer for it," said Greens senator Larissa Waters.  "After years of the government denying climate science and saying water quality not climate is the biggest threat to the Reef, now it (has set up) an inquiry into whether water quality really is a problem for the Reef."

The critics allege the inquiry is a cover to debate the ideas of the controversial climate change-denying scientist Peter Ridd, who became a conservative celebrity when he was sacked by James Cook University and won a $1.2 Million settlement.  Ridd's most recent gig has been a speaking tour supported by the sugarcane industry claiming that farmland pollution does not significantly damage the Great Barrier Reef.  Former chief scientist Ian Chubb argues that Ridd is misrepresenting the science regarding the plight of the reef, likening it to the way the tobacco industry to raise doubt about the impact of smoking.

But finance minister Matthias Cormann insists the coalition was "absolutely committed to the health of the Great Barrier Reef" and backed the proposed inquiry as "an opportunity to do even better protecting the Great Barrier Reef into the future".