Opposition leader Peter Dutton has gone off-script with a personal attack on Prime Minister Anthony Albanese and set the stage for a nuclear showdown in the lead-up to the next election.

Dutton spruiked his uncosted nuclear plan during an address to the party faithful on Saturday and took a personal swipe at Albanese, veering from pre-written speech notes distributed to the media.

He said memes of three-eyed fish and koalas distributed by senior Labor MPs in recent days showed “the juvenile nature of our prime minister”.

“He’s a man with a mind still captured in his university years; he’s a child in a man’s body,” Dutton told the loyalist audience.

“We need a mature conversation in this country,” he added.

The coalition has pledged to build nuclear reactors across five states on the sites of coal-fired power stations if it wins government at the next election.

Dutton made clear his nuclear energy policy would form the centrepiece of the election debate.

“The next election will not only define the next political term — it will define the future and fate of this nation,” he said.

He described Albanese as “a political appeaser, not a leader of conviction” and said the PM “places a higher value on political survival than statesmanship”.

Dutton vowed that states opposed to building nuclear power plants would be overridden if he won office.

He responded to promises of refusal from NSW and Victorian premiers Chris Minns and Jacinta Allan to build nuclear power plants in their states.

“I don’t answer to them,” he shot back.

“Commonwealth laws override state laws … so support or opposition at a state level won’t stop us rolling out our new energy system.”

His blast came as the Smart Energy Council said the cost of building seven reactors could be up to $600 billion and “at best” deliver just 3.7 per cent of Australia’s energy mix in 2050.

The Smart Energy Council estimated the cost to taxpayers to be at least $116 billion.

The cost is the same as delivering 82 per cent renewables by 2030, and an almost 100 per cent renewable energy mix by 2050, including the cost of building all of the enabling transmission infrastructure, the council said.

The figures are based on data from the CSIRO’s latest GenCost report and the Australian Energy Market Operator’s Integrated System Plan.

Assistant Climate Change and Energy Minister Jenny McAllister said Dutton lacked any policy detail or costs for his plan.

She accused him of proposing “a risky, untested experimental technology with no costs associated with it, and lack of clarity about how it will be rolled out”.

“(He) is always about the politics and never about the policy,” she told reporters on Saturday.

“Mr Dutton may wish to resort to personal attack but it is no substitute for actual policy.”

“The bill will be met by energy users, the risks will be borne by taxpayers, and the costs will be borne by the communities that miss out on the jobs that will come about as the world moves to net zero,” she said.

The coalition on Wednesday unveiled plans for seven nuclear reactors across five states on the sites of coal-fired power stations, should it win government.

The plan prompted safety concerns in regional areas where the reactors are due to be built, as well as criticism the coalition had not released any costings.

Under the plan, it would take until 2035 to 2037 at the earliest for the first facility to be built.

$600 billion cost

Smart Energy Council chief executive John Grimes said Dutton’s nuclear proposal would deliver “at best” 3.7 per cent of the energy required at the same cost as the government’s current strategy.

“In reality, current cost overruns happening right now in the UK could mean a $600 billion bill to Australian taxpayers, whilst delivering a small proportion of the energy that is actually required,” he said.

Grimes said nuclear had no place in a country with cheap, reliable energy powered by the sun and wind and backed up by renewable energy storage.

“The most optimistic assessment of Peter Dutton’s nuclear proposal indicates it is a pale shadow of the reliable renewables plan outlined and costed by the Australian Energy Market Operator,” he said.

The council has called on the opposition to release its analysis of the costings and generation capacity from the seven proposed nuclear reactor sites.

“They need to explain how their forecasts contradict the experts at the CSIRO and AEMO,” Grimes said.

“It is extraordinary that the details are being hidden from the Australian public.”

Nuclear showdown

The fallout from the opposition’s proposed nuclear reactors is set to send Parliament House into meltdown, as the cost of living continues to dominate the political conversation.

Both the Senate and the House or Representatives will sit from Monday to Thursday for the next two weeks as parliament embarks on its final fortnight before a mid-year break.

A nuclear war of words will likely play out during Question Time after the coalition on Wednesday announced it would build seven plants at the sites of coal-fired power stations if it wins the next election.

Albanese has called the proposition a “fantasy”, noting the opposition had not released many details nor announced how much it would cost.

It would also squander the nation’s potential as Australia is well positioned to take advantage of resources like wind and solar, Mr Albanese said.

Plants would be built at Loy Yang in Victoria’s Gippsland region, Callide and Tarong in Queensland, Mount Piper at Lithgow in central west NSW and Liddell in NSW’s Hunter region.

Small modular reactors would be located at Port Augusta in South Australia and Muja, in WA’s South West region.

Though Dutton acknowledged it would be “a lot of money”, he said Australians were struggling to pay their energy bills and claimed the policy would eventually bring power prices down.

But energy bill relief is already on the horizon for Australian households with the government’s $300 rebate set to kick in after July 1.

Labor’s defences against cost-of-living jabs will also be bolstered by their tax cuts and the Fair Work Commission’s 3.75 per cent increase in minimum wages – both of which will come into effect at the beginning of July.

-with AAP