The Coalition has relaunched its policy to establish an environmental workforce - a Green Army - but has slashed its funding by a quarter.

Opposition Leader Tony Abbott launched the idea in 2010 in his first major policy speech leading up to that year's federal election.

Then, the Green Army was slated to cost $400 million over the forward estimates, but the Coalition says it will now allocate $300 million over its first four years.

Mr Abbott says the Green Army would be a national conservation workforce of around 15,000 primarily young people.

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He says the project "puts together our two greatest assets, our land and our people; our beautiful environment with our idealistic young people".

"This is a $300 million policy over the forward estimates period and we believe that the $300 million over the forward estimates period will get us at least 1,500 Green Army teams to operate around Australia," he said.

Opposition environment spokesman Greg Hunt says there are two simple reasons behind the funding cut.

"Firstly, Labor scrapped the green jobs program which was the basis for implementing Green Army, so we obviously need to re-establish that structure," he told PM.

"Secondly, we do need to respond to the financial challenge with the ALP has left for any incoming government.

"We'll still achieve our 15,000 young people in the same timeframe, but because the infrastructure has been completely destroyed by the ALP we start a little more slowly."

The Coalition plans to have 250 teams of 10 people ready to start work by next July.

Each team will be comprised of nine trainees - paid a training wage of around $400 a week - and one coordinator on an annual salary of more than $60,000.

Workers would carry out remediation and conservation projects such as cleaning up riverbanks and revegetating sand dunes.

Policy to have have projects in every state

The Opposition has announced five projects along the Georges River in Sydney but says there will be projects in every state.

Mr Hunt says the process of choosing sites will involve local community input but will "of course" involve the minister.

The policy is part of the Coalition's "direct action" plan to reduce carbon emissions without a carbon pricing scheme.

But Environment Minister Mark Butler says it is a scaled down version of an old policy.

"At the time it was not properly costed and poorly designed," he said.

"It remains poorly designed and funding has been cut with a fraction of the projects originally proposed.

"The Liberal-National Coalition is simply green-washing their real plan to wreck the environment with cuts to climate change and environment programs."

The Labor government has dismissed the Green Army as being unfunded and doing nothing to address climate change.

The Australian Conservation Foundation says revegetation is "useful" work but is an inefficient way to tackle climate change.

"While revegetation is useful and important work, it does nothing to slow industrial emissions, which are the big driver of climate change," ACF climate change campaign Claire Maries said.

"This plan proposes using taxpayers' money to plant trees, while big polluters continue to pollute for free.

"A carbon price makes polluters pay, giving them an incentive to cut their emissions."