Energy Minister Chris Bowen has attacked the Nationals for suggesting nuclear power be considered in Australia's energy mix, saying the party had no credibility after nine years in government.
Mr Bowen says nuclear would be the most expensive form of energy when Australians are already facing rising costs and inflationary pressures.
"Seriously? Nine years in office and then coming up with bright ideas on the other side of the election is point one. No credibility," he said on Thursday.
"Nuclear is the most expensive form of energy. We have a cost of living crisis, energy prices going through the roof and what's their big bright idea? Let's have the most expensive form of energy we can possibly think of."
The comments come after the Nationals said it doesn't make sense for Australia to be the only country in the G20 group to ban nuclear power.
Nationals leader David Littleproud has written to Prime Minister Anthony Albanese asking for serious consideration of small-scale nuclear power.
But Labor has rejected the technology as too expensive and not a serious solution to reducing power costs or cutting emissions.
Nationals deputy leader Perin Davey said it was time for Australia to examine the benefits of nuclear technologies, in terms of cost, emissions and energy security.
"We are the only country in the G20 that has a legal ban on nuclear power," Senator Davey told Sky News on Thursday.
"Yet we're the third largest uranium producer in the world."
She said if the government supported a technology-based transition to net zero emissions, nuclear must be in the mix.
"Australia's got to move on - it's no longer the 70s and 80s, we no longer have the Nuclear Disarmament Party and even Greens voters are saying nuclear should be considered because it is zero emissions power."
The ageing of coal-fired power stations made it even more urgent, she said.
NSW energy minister Matt Kean said people talking about nuclear energy were "literally chasing unicorns".
Assistant Treasurer Stephen Jones said it did not make sense to invest in something "that won't generate one new watt of electricity for 10 years".
"And as much as it runs on uranium as a power source, it is also running on government subsidies because there is no way that we can have nuclear generation in energy in this country that cannot operate without generous government subsidies for decades to come," Mr Jones said.
He questioned why the coalition, which had been in power since 2013, had not taken the idea forward in government.
"The answer is, it's not viable. It doesn't make sense for Australia," he told Sky News.
Victorian energy minister Lily D'Ambrosio said nuclear technology was the "last thing" a government would use to lower power prices.
"Not to mention the fact that it produces toxic waste that is in our environment for centuries, if not thousands of years," she told reporters.
A survey by free market think tank, the Institute of Public Affairs, published this week found 53 per cent support for nuclear power, with 24 per cent of people responding neutrally and 23 per cent disagreeing.