With elections looming by May 2025, the conservative opposition has proposed nuclear power as a way to cut carbon emissions with less reliance on solar panels and wind turbines.

Critics say nuclear power plants would cost far more than renewable energy sources and arrive far too late.

Australia's national science agency CSIRO said in a report this week that nuclear power would be 50 percent more expensive than renewables and would take at least 15 years to build.

But opposition Liberal Party leader Peter Dutton said his proposal -- which would require overturning Australia's 26-year nuclear ban -- would lead to comparatively lower costs and a more reliable electricity supply.

"It will keep the lights on. And it will set our country up for generations to come," Dutton told reporters as he unveiled his nuclear option's costings for the first time.

The nuclear plan would cost Aus$331 billion (US$210 billion) over 25 years, the opposition said, providing about 38 percent of the country's energy by 2050, with wind and solar contributing 50 percent.

It would rely on keeping coal-fired power stations open for longer than currently planned, despite energy companies already preparing to close them.

The nuclear costing, conducted by Frontier Economics, also reportedly assumes that electricity demand will not grow by as much as the government expects.

"The truth is that renewables are the cheapest form of new energy," said Prime Minister Anthony Albanese, deriding the opposition's costings as "fiction".

"Everyone knows that that's the case and science tells us that that's the case," he told national broadcaster ABC.

Australian Conservation Foundation chief executive Kelly O'Shanassy said the nuclear modelling was "full of holes".

For a fraction of the cost of nuclear power, rooftop solar panels could be installed on every house in the country, O'Shanassy said.

"We would be waiting at least 20 years for the reactors. That is far too slow to be an effective response to the climate crisis, which is affecting Australians right here, right now," she said.

"We don't have two decades to waste."

Polling released by the Lowy Institute think-tank this year showed Australia's longtime scepticism about nuclear power had "shifted markedly", with six in 10 Australians supportive of some form of nuclear energy.

Over the past decade, an ideological brawl dubbed the "climate wars" has dominated Australian politics, repeatedly undermining attempts to reduce carbon emissions.

More than 30 percent of Australia's total electricity generation in 2022 came from solar and wind and the country has committed to reaching net zero greenhouse emissions by 2050.