And he has bolstered that move with a formal commitment to keep the Clean Energy Finance Corporation, and the Australian Renewable Energy Agency, both of which had been set for abolition under Mr Abbott’s leadership.

“Clean energy is central to the government’s strategy to address climate change and meet our emissions reduction targets,” Mr Turnbull said.

The policy is the culmination of extensive background work by Environment Minister Greg Hunt over a period of two months.

The green shift marks a significant policy departure from the minimalist climate platform of the Abbott government and came as tensions between the two figures reached Rudd-Gillard levels on Tuesday, playing directly into the opposition’s hands.

On what was the first day of an extended quasi-election campaign, which could yet end with a Senate deadlock and a double dissolution election on July 2, Cabinet resolved to overturn the longstanding Abbott government antipathy to the CEFC – sometimes referred to as the “green bank” – and to add another body to the nation’s climate change architecture in the form of the entirely new Clean Energy Innovation Fund.

The government says the $1 billion CEIF will “drive innovation and create the jobs of the future, while delivering a financial benefit from the investment of public money”.

It will be financed with an annual allocation of $100 million from the CEFC over each of the next 10 years.

But it will not disburse grants. Instead it will offer a mix of “innovative equity and debt products” – code for buying shares in and lending money to, new technology renewable energy ventures.

It is intended that the CEIF will target everything from smart grids, and bio fuels to large-scale solar energy projects with storage capacity.

The new body will commence operations as soon as July. It will sit between the existing $10 billion green bank, and draw expertise from the Australian Renewable Energy Agency – another body which had been on political death-row under the Abbott government.

The government believes the new CEIF will “fill a gap”, providing equity and debt financing to projects that are designed to return a profit and which have not been eligible for funding under the models of the two parent bodies to this point.

It coincided with a dangerous tit-for-tat exchange with Mr Abbott conducted via duelling broadcast interviews, which has government MPs warning it must not be allowed to continue during an election year.

The spat saw Mr Turnbull slap down the Abbott claim that the government was merely running on the Abbott record.

Government MPs are under no illusion as to the electoral risks arising from having a leader and ex-leader at war, citing the recent bitter divisions between Kevin Rudd and Julia Gillard on the Labor side, to argue Mr Abbott must now desist in the interests of the party.

However, there are no signs of peace breaking out any time soon.

Mr Abbott used a Sky News interview from London, apparently calculated to steal the headlines on the very same day as Mr Turnbull’s daring double-dissolution ultimatum to the Senate, to declare: “It’s very easy for me to campaign for the election of the Turnbull government because the Turnbull government is running on the Abbott government’s record and it’s a very strong record.”

The comments angered the Prime Minister, prompting him to dismiss Mr Abbott’s signature achievement of stopping asylum-seeker boats during his time in office.

“This is not something that was invented by Tony Abbott, this has been a continuum,” Mr Turnbull said on Melbourne radio, reminding voters that the policy of mandatory off-shore detention had been in place in the Howard years, and had remained as core Coalition policy during 2008-09, when Mr Turnbull had been leader of the opposition.

MPs, many of whom are sitting on small margins in their electorates, believe the government can ill afford distractions, with even committed Abbott loyalists calling on him to desist as an election approaches.

“You can’t be seen to help Labor,” said one former Abbott loyalist. “It’s battle-faces on now, and this thing is getting silly.

“There is a commonly held view that enough is enough,” the MP said.

“He (Mr Abbott) is regarded very fondly but he is not going to endear himself with these kinds of comments.”

Another source said Mr Abbott “would not be doing this to help Labor, but that is the result”.

As if to validate that assessment, opposition leader Bill Shorten surprised few by immediately agreeing with the Abbott assessment.

“The legislation Mr Turnbull has in the Parliament, 80 per cent of it was designed, dreamed up, and driven by Tony Abbott when he was leader,” Mr Shorten said.

“Now, under Mr Turnbull’s leadership, we still see the same cuts to Medicare, we still see the same cuts to schools and hospitals, we see the same inaction on renewable energy and climate change.

“It doesn’t matter who’s running the Liberal Party, Tony Abbott or Malcolm Turnbull, it’s all continuity, no change.”

But having Labor and the former prime minister running the same criticism, did not appear to worry Finance Minister Mathias Cormann.

The unflappable conservative, who has successfully straddled the leadership ructions to remain highly influential in both cabinets, argues the election will be based on voters’ assessment of what the government has planned for the nation, buttressed by an established record of delivery.

“As the Prime Minister said, there is inevitably a lot of continuity; from the Prime Minister down, a whole number of us were senior members of the Abbott government. Inevitably, there is a level of continuity but, what people across Australia will be interested in when they pass judgment on who to support in the lead-up to the next election is obviously assessing the plans of the respective teams about the next three years,” he said.