Queensland National Matt Canavan has signalled he is prepared to defy his party room if a majority accepts a commitment to net zero, as his Victorian colleague Darren Chester – who supports an aspirational mid-century target – will take a break from the National party.

Tensions within the junior Coalition partner erupted on Sunday, with Canavan telling Guardian Australia he was just warming up when it came to opposing any net zero by 2050 pledge by the Morrison government, and Chester confirming a hiatus because of profound differences with the current Nationals leadership.

With the National party riven, and the Cop26 summit in Glasgow bearing down, the deputy prime minister Barnaby Joyce and the Nationals deputy leader David Littleproud fronted separate television interviews on Sunday morning.

Asked to state his view on a net zero commitment, Joyce at first told the ABC no coal jobs should be lost “by reason of domestic policy”. But shortly after that declaration, he said protecting coal jobs was “not the bottom line”.

On Sky News, Littleproud leaned in to a net zero commitment, arguing his party needed to be “pragmatic”. Littleproud also insisted if a majority of Nationals ultimately supported net zero when the issue was considered by the party room, then everyone needed to get behind that decision.

“The party room always works on majority,” Littleproud said. “There’s always diverse views within the party room, that’s a good thing, that’s this beautiful thing called democracy and we should encourage it, not discourage it.

“Maybe people at the end have a different view, as I have sometimes in that party room, [but] they will come out and support what the party has said”.

Littleproud echoed arguments the treasurer Josh Frydenberg articulated last week about the economic case for a net zero commitment. He said Scott Morrison was promising a “technology pathway” for the transition.

He said Morrison had “clearly gone away and thought through the problem, working through this technology roadmap that will protect regional Australia – that’s what he’s said from the start and I take him on his word, I have no reason not to”.

Asked to respond to Littleproud’s declaration about the party room falling into line, Canavan – who is implacably opposed to a net zero commitment – told Guardian Australia: “I am deadset against net zero emissions – just look at the disaster the United Kingdom is living through.

“I haven’t even begun to fight,” Canavan said.

After Frydenberg’s forward-leaning speech last week, another Queensland National, the resources minister, Keith Pitt, also signalled dissent, declaring resources industry jobs were more important than “demands from foreign countries or the United Nations”.

But Chester – who has become increasingly concerned about Joyce’s reluctance to rein in his close supporters – as well as the party’s former leader Michael McCormack, last week made the case for the Nationals to either support net zero or approach the issue with an open mind.

Chester has told Guardian Australia he is not quitting the National party, only taking a break. In a statement issued on Sunday, the MP – who lost his frontbench spot when Joyce returned to the Nationals leadership – said he would reassess his position before federal parliament resumes in mid-October.

He said he would continue to support the Morrison government, but the decision to step back came after “months of frustration with the repeated failure of the leadership to even attempt to moderate some of the more disrespectful and offensive views expressed by a minority of colleagues”.

The government wants to unveil updated climate commitments next month, ahead of the Cop26 in November. Government sources have told Guardian Australia the energy and emissions reduction minister, Angus Taylor, is telling colleagues privately that the government could try to appease the Nationals trenchantly opposed to the 2050 target with a halfway house ahead of Cop26.

The government could decline to explicitly endorse the specific mid-century commitment, while announcing a roadmap of actions that would set Australia on the net zero path.

But this landing point would be unacceptable to metropolitan Liberals who believe Australia needs to make this transition, rather than pretend to make the transition.

Morrison is also facing diplomatic pressure from the United States, the United Kingdom and European countries to sign up to net zero, and to make Australia’s 2030 commitment more ambitious.

Morrison told the Seven Network on Sunday Australia needed to get to net zero and “we’ve been working on a plan of how we can achieve that”.

“What I’ve been working to do is to bring my government together to get a plan that we can take to the Australian people and show to the Australian people, to say we can deal with this, we can do this, but we can do it without having to tax people,” Morrison said.

“We can do it without having to shut down our industries and regions. My task has been to bring my government together on this issue and to focus on how we can get it done.”

Joyce on Sunday did not rule out coming to an agreement with Morrison but he refused to be specific about what his red lines were.

The deputy prime minister said Australia was not in a position to shut down coal exports because of the income earned from selling fossil fuels offshore. He said the Nationals needed to safeguard the economic wellbeing of regional towns reliant on income from the coal industry.

When it was put to him that Chester was taking a break from the Nationals because of his failure to rebuke outspoken colleagues like the Queensland backbencher George Christensen, Joyce said he was not in a position to “gaffer tape [Christensen’s] mouth up”.

Asked whether he would attempt to patch up his differences with Chester, Joyce said: “We have a party meeting every Monday.”