The Greens would demand an immediate moratorium on new coal, oil and gas projects in return for supporting Labor, if the federal election leads to a hung parliament.

With the election due before the end of May, Greens Leader Adam Bandt is seeking to set the terms of potential negotiations, should his party hold the balance of power in either the House of Representatives or the Senate.

The Coalition has referred to the prospect of the Greens influencing Labor policy in its efforts to convince voters not to trust the ALP on climate policy.

For the Greens, a moratorium on new coal, oil and gas developments is a significantly weaker climate position than their policy platform, which calls for a rapid phase-out of fossil fuels.

They envisage a moratorium be put in place while more extensive negotiations take place about climate action.

"It's not even about existing coal and gas projects, we're just saying don't open up new ones."

"We have differences of views about how quickly we should get out of existing coal and gas, but everyone can surely agree that we shouldn't open up new coal and gas projects."

Greens target 75 per cent emissions cut by 2030

The Greens have promised not to block Labor's efforts to legislate more substantive climate action, instead vowing to work with the ALP in the lead up to the next international climate talks in Egypt in November.

The ALP has promised to set targets of reducing greenhouse gas emissions by 43 per cent by 2030 and reaching net zero by 2050.

However, the Greens want a 75 per cent reduction in emissions by 2030 and to hit net zero emissions by 2035.

The Coalition's policy has remained unchanged since 2015, with a 26-to-28 per cent reduction by 2030, though emissions are currently projected to fall by at least 30 per cent by then.

The Greens' idea of a moratorium is in part an attempt to neuter the Coalition's scare tactics that the Greens will force Labor to take radical positions on climate policy.

But the promise to work constructively with Labor on legislation also appears to acknowledge criticism the Greens have faced in the past over its scuppering of Labor's Carbon Pollution Reduction Scheme in 2009 for not being ambitious enough, only to end up with no legislated emissions trading scheme at all.

"I'm sure we can work with Labor to pass their climate legislation before the next climate summit to help boost climate action worldwide, but opening up new coal and gas mines is a problem," Mr Bandt said.

"With everyone from the International Energy Agency to the United Nations saying there must be no new coal and gas projects, this temporary freeze is a modest demand that no sensible government could reasonably refuse."

The Labor Party supports new gas exploration and development and has previously said the development of new coal mines would be decided by market economics.

The ALP recently backflipped on its opposition to the federal government backing a new gas-fired power plant in the Hunter Valley, instead promising to switch it to run on clean hydrogen power instead.

The Greens hold only one seat in the House of Representatives, with other independents and minor parties also having the potential to negotiate a power-sharing agreement with the major parties in the event of a hung parliament.

The Greens have more sway in the Senate, where they currently hold a block of nine seats.