Putting aside the vexed issue of climate until the Coalition has forged its policy, Mr Abbott admitted the environment would be a vote-changer, but said the debate should be ''much more than an argument over climate change''.

''The political left shouldn't be seen as 'owning' the environment,'' he said. ''And I am determined to challenge any assumption that it does.

''Conservative political parties and the conservationist movement both want to preserve what's best in our heritage,'' he told the Sydney Institute in his initial policy speech as leader.

Mr Abbott, a self-described ''practical environmentalist'', said he had always been a conservationist and, in a pitch for green preferences, said it was ''high time that the green movement re-thought its habitual preference for Labor, because actual environmental improvements are more likely to come from conservative governments (that get things done) than from Labor ones (that have a tendency to lock up land without maintaining it)''.

Mr Abbott nominated Australia's biggest environmental problem as ''reconciling the human, economic and environmental demands on the Murray-Darling basin'', a situation bedevilled by the fact ''that no one is really in charge''.

A future Coalition government - like the Howard government - would invite the states to refer their powers to Canberra, he said.

If by mid-2012, the states still refused, the Coalition would seek power in a referendum held with the 2013 election.

Mr Abbott said Australia was losing the battle against environmental degradation - there was not a sufficient labour force to deal with weeds, feral animals and infrastructure needs.

He would talk with green groups about a Coalition government setting up a 15,000-strong ''standing green army'' or ''land army'' of short-term trainees, plus regular workers, able to work on ''large-scale environmental remediation needs''. It would be Australia's ''first deployment of large numbers of people on behalf of the environment,'' he said.

At an average cost per place of $50,000 a year, a 15,000-strong corps would be expensive ($750 million), but the Coalition would announce savings and revenue measures to fund it, he said.

Climate Change Minister Penny Wong said Mr Abbott's ideas were ''ineffective, uncosted, unfunded policies that will do nothing to address climate change''.