The Liberal frontbencher Andrew Bragg says any “fatwa” waged against the words net zero is “ridiculous”, as the moderate senator threatened to quit the frontbench if the party dumps the target and withdraws from the Paris climate agreement.

Bragg’s ultimatum piles further pressure on the opposition leader, Sussan Ley, ahead of a series of high-stakes meetings this week to settle the Coalition’s position on net zero emissions.

Ahead of the meetings, the opposition’s energy spokesperson, Dan Tehan, signalled support for extending the life of coal-fired power stations – possibly with the help of taxpayer subsidies – as part of a strategy to reduce prices through “energy abundance”.

Liberal MPs will reconvene in Canberra on Wednesday to debate the pillars of the party’s energy platform, including its commitment to net zero emissions, before the Liberal shadow ministry meets on Thursday to ratify a position.

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A joint party room meeting has been scheduled for Sunday 16 November to endorse a joint position with the Nationals. The junior coalition partner has already decided to abandon net zero.

Bragg is among a group of mostly moderate Liberals fighting to salvage some commitment to carbon neutrality after senior conservatives turned against the policy, encouraging Ley to not only jettison the Scott Morrison-era 2050 target, but any reference to net zero at all.

It means Ley faces an internal backlash that will intensify pressure on her leadership regardless of which position she lands.

Guardian Australia last week reported a view among some Liberals that the term “net zero”, as much as the substance of the policy, had become toxic in the political debate.

Asked on Sunday if Ley could survive as leader if she caved to conservatives and adopted the Nationals’ clean break from net zero emissions, Bragg criticised the campaign against the target.

“You can’t have a fatwa on two words. This [net zero] is the international standard. I mean, trying to pretend you’re not going to say two words is absolutely ridiculous,” the shadow housing minister told ABC’s Insiders.

“Australia is part of the international community. It is not actually the net zero accord which is driving higher power prices. It is Labor’s disastrous energy policies.”

Speculation of frontbench resignations and the Coalition potentially splitting, again, resurfaced as moderate Liberals weigh up their options if their party adopts the Nationals’ position.

Bragg was pushed several times on Sunday on whether he would resign from the shadow ministry if the Liberals dumped net zero entirely and walked away from the Paris agreement.

“Well, sure, but I don’t imagine that we’ll ever leave Paris. I mean, we are a party of government, right. We are not a fringe party, we’re not fringe dwellers,” he said.

There is no serious talk that the Coalition would commit to following Donald Trump’s lead and withdraw Australia from Paris.

Even the Nationals don’t support pulling out of Paris despite ditching net zero.

As of October, 145 countries had announced or were considering net zero targets, according to Climate Action Tracker, meaning that not all signatories to Paris have individual commitments to the goal.

If a future Coalition government were to remain in Paris but water down Australia’s existing pledges – including the target of net zero by 2050 – it would breach the pact, which dictates countries can’t go backwards on targets.

In an earlier interview on Sky News, Tehan would not preempt the outcome of this week’s meetings.

The frontbencher said the party was focused on delivering lower energy prices through “energy abundance”, which could require extending the life of ageing coal-fired power stations and pumping more gas into the market.

He did not rule out taxpayer subsidies for fossil-fuel power generation.

“Now what I’m saying is we need to make sure that we’re sweating those coal assets, continue to sweat those coal assets, and also that we can get more gas into the system much more quickly,” he said.

The Queensland LNP government’s new energy roadmap, released last month, proposed keeping its state-owned coal plants running for up to a decade longer than previously planned, meaning some would be open until at least 2046.

Critics – including energy analysts and conservationists – said the plan would saddle Queenslanders with expensive and unreliable energy that would damage the climate.