Malcolm Turnbull has launched a swingeing attack on Scott Morrison’s gas-led recovery, labelling his threat to build a gas-fired power station “crazy stuff”, and his idea of gas producing a cheap energy boom “a fantasy”.

The former prime minister also claimed Morrison’s refusal to embrace a 2050 net zero emissions target was “absolutely” at odds with the Paris climate agreement. “That was part of the deal,” Turnbull said.

Morrison at the weekend would not commit to a 2050 target – endorsed by business, farming and other groups in Australia and very many countries – although he said it was achievable.

Turnbull also declared that Energy Minister Angus Taylor – who on Tuesday delivered his technology investment roadmap for low emissions – didn’t believe most of what he was saying on energy.

“Angus has got quite a sophisticated understanding of the energy market, and he is speaking through the political side of his brain rather than the economic side,” Turnbull told the ABC.

The energy/climate war was pivotal in Turnbull’s fall from the prime ministership in 2018, and from the opposition leadership in 2009. While Morrison is totally safe in his job, the battle over energy policy on the conservative side of politics has not been put to rest, although the prime minister is banking on his elevation of gas satisfying his Liberal parliamentarians.

Morrison’s gas policy, which the government spruiks as underpinning a manufacturing revival, is being seen as a walk away from coal.

It includes a threat to build a gas-fired power station in the Hunter region if private enterprise does not fill the gap left by the coming closure of the Liddell coal-fired station.

The debate about gas has produced an unexpected unity ticket between Turnbull and former resources minister, the Nationals Matt Canavan, on one key point - both insist gas prices won’t be as low as the policy assumes.

But Turnbull and Canavan go in opposite directions in their energy prescriptions – Turnbull strongly backs renewables and Canavan is a voice for coal.

While acknowledging gas had a role “as a peaking fuel”, Turnbull dismissed any prospect of a “gas nirvana”.

“There is no cheap gas on the east coast of Australia. It is cheap at the moment because there’s a global recession and pandemic and oil prices are down, but the equilibrium price of gas is too high to make it a cheap form of generating electricity.”

“The cheap electricity opportunities come from wind and solar, backed by storage, batteries and pumped hydro, and then with gas playing a role but it’s essentially a peaking role,” Turnbull said.

Writing in the Australian, Canavan said the Morrison gas plan would “keep the lights on but it is unlikely to lower energy prices to the levels needed to bring manufacturing back to Australia.

"If we were serious about getting [energy] prices down as low as possible, we would focus on the energy sources in which we have a natural advantage, and that is not gas. We face gas shortages in the years ahead.”

Former Nationals leader Barnaby Joyce said about the government’s power station threat, that it would be “peculiar” to build a gas-fired plant “in the middle of a coal field”.

Turnbull said of last week’s announcement, “I’m not going to sing the song but it’s a gas, gas, gas”.

The roadmap was “gas one minute, carbon capture and storage the next”.

“What you need is to set out some basic parameters, which deal with reliability, affordability and emissions reduction, and then let the market get to work. That’s what Liberal governments should do. Unfortunately, it’s just one random intervention after another,” Turnbull said.

He lamented that, for whatever reasons, there was a “body of opinion on the right of Australian politics in the Liberal party and the National party, the Murdoch press, which still clings to this fantasy that coal is best and if we can’t have coal we’ll burn gas – I mean, it’s bonkers. The way to cheaper electricity is renewables plus storage, which is why the big storage plan that we got started, Snowy 2, is so important.”

Turnbull said that unlike his own situation when PM, Morrison was “in a position with no internal opposition”. “Now is the time to deliver an integrated, coherent energy and climate policy which is what the whole energy sector has been crying out for.”

Taylor told the National Press Club the government’s determination to get the gap filled, whether by private investment or a government power station, when the Liddell coal fired station closes in 2023 “is partly about reliability, but it’s primarily about affordability.

"If you take that much capacity out of the market, it’s a huge amount in a short period of time. We saw what happened with Hazelwood. We saw very, very sharp increases in prices. We’re not prepared to accept that.”

Asked whether the government’s resistance to committing to the 2050 target was more about appeasing the right wing of the coalition rather than about the target itself, Taylor said: “Our focus is on our 2030 target in the Paris agreement…and in a few years time we will have to extend that out to 2035 …

"What we’re not going to do is impose a target that’s going to impose costs on the economy, destroy jobs, and stop investment. The Paris commitment, globally, is to net zero in the second half of the century and we would like that to happen as soon as possible.”