Australia won’t be able to meet its targets for reducing carbon gas emissions without charging polluters, Prime Minister Julia Gillard said on Friday as she announced her government’s climate change policy ahead of elections next month.

Both the centre-left government and conservative opposition coalition have promised to cut Australia’s greenhouse gas emissions by at least 5 percent below 2000 levels by 2020. But they have fundamentally different plans to achieve that cut.

The ruling Labour Party would sell permits to polluters that would allow them to emit carbon gas, while the opposition Liberal Party would give polluters taxpayer-funded incentives to introduce cleaner technologies. The Liberals would not penalize polluters for emitting more carbon.

Australia is one of the world’s worst greenhouse gas emitters per capita because of its heavy reliance on abundant reserves of coal to generate electricity.

Gillard announced Friday that she would appoint 150 people to decide over the next year how the permit system would be implemented.

She said Australia’s carbon emissions would increase under her opponent, opposition leader Tony Abbott.

“There is no responsible government in the world, no credible organization, that is advocating this way of approaching the challenge,” Ms. Gillard said of the Liberals’ policy.

“To reduce carbon pollution to meet the targets that we have set ourselves ... the only way you can do that is by having a price on carbon,” she added.

Both the government and opposition went into the last election in 2007 promising to introduce a system in which polluters would have to pay for permits to emit carbon gas. The number of permits would be limited so that industries would have to become cleaner over time.

But the Liberals under Abbott abandoned that policy after the United Nations summit on climate change in Copenhagen last December failed to agree on binding national emission targets.

Gillard’s predecessor, Kevin Rudd, had described climate change as the greatest moral challenge of his time and had ratified the Kyoto Protocol on Greenhouse gas emissions as his first act as prime minister.

His popularity plummeted in opinion polls in April after he shelved his emission permit trading scheme until 2013. He argued that he had no hope of getting his legislation through the Senate because the Liberals had changed their policy. Ms. Gillard replaced Mr. Rudd in a sudden internal Labour coup last month.

Abbott said Labour’s plan would cause electricity prices to rise and would cost jobs.

He said how Labour’s policy was implemented should be decided by lawmakers rather than members of the public.

“This is a decision for the parliament and she can’t subcontract out leadership to some kind of giant focus group,” Abbott said.

Australian National University economist Warwick McKibbon said appointing the 150-member so-called Citizen’s Assembly appeared to be an excuse to delay action on climate change.

Opinion polls suggest that Labour will win a second three-year term at elections on Aug. 21.