Sussan Ley is resisting growing internal pressure for the Coalition to quickly discuss and determine the future of its policy on net zero.

A number of Liberals and Nationals urged the debate be brought forward and the process for decision making clarified, at the Liberal and Coalition party meetings on Tuesday.

The pressure reflects the surge in support especially in the Nationals – but also in parts of the Liberal Party – for dumping the 2050 net zero commitment. More generally, it is becoming increasingly politically untenable for the Coalition to remain in limbo over its policy.

The opposition’s hand is also being forced by the fact the government will announce within weeks Australia’s 2035 emissions reduction target under the Paris agreement. This target, which may be a range rather than a particular number, appears likely to between 65% and 75%, on previous indications. Australia’s 2030 target is a 43% reduction on 2005 emissions.

Sources said Tuesday’s push started in the Liberal party room meeting with the matter raised by South Australian conservative Tony Pasin and then continued at the joint party meeting.

A range of speakers including both conservatives and moderates, with differing positions on net zero, argued the Coalition needed to get on with settling a position.

Initially, the need for a position was about a 2035 target and then broadened into the need to settle its position on net zero.

Pasin later told Sky he had sought clarification on the process for making the decisions but didn’t get it. He said the opposition could not wait 12-18 months to decide a policy.

High profile Nationals Matt Canavan and Barnaby Joyce are running an intense campaign to change the Coalition’s policy. The government is ensuring Joyce’s private member’s bill to remove legislative references to net zero is regularly debated in the time given each week to private member’s bills.

The Nationals seem certain to dump net zero sooner rather than later, while the Liberals are divided and Ley is trying to stick to her timetable of a comprehensive Coalition review before a decision is made.

The review team includes representation from the Nationals, and is chaired by Victorian Liberal Dan Tehan, who is energy spokesman.

Tehan told Sky on Tuesday, “I’ve said quite clearly on the record a number of times that I support net zero by 2050”.

Last Friday the Queensland Liberal National Party convention overwhelmingly rejected net zero. Meetings of the Liberal organisations in South Australia and Western Australia had done so earlier.

While the party organisation can’t impose policy on the Liberal parliamentary party, the stands increase the pressure on MPs, who have an eye to their preselections.

Frontbencher Andrew Hastie is not waiting for the review. He told the ABC on Tuesday, “I believe in a sovereign, secure, competitive and prosperous Australia, and I think net zero undermines that very thing”. Hastie has been outspoken on the issue before.

The Liberal leader in the senate, and fellow Western Australian, Michaelia Cash, has backed the WA motion against net zero.

Labor predictably capitalised on the Coalition’s problems with its energy policy, with Energy Minister Chris Bowen telling parliament, “What we have is two parties, one Coalition, and many, many ways of killing net zero”.

Ley told a news conference Labor’s coming announcement of its 2035 targets would give the opposition an opportunity to ask the government to demonstrate what these targets will cost, how it would deliver on promises and what they would mean for manufacturing businesses and Australian households.

Deciding the 2035 target finds the government caught between ambition and practicality. For the opposition, the government’s announcement will put it on the spot – but, if the internal heat becomes too much, it would also provide an opportunity to deal with the net zero issue. That would mean, however, dramatically accerelating the Tehan review and the policy-making process.

Whether she sticks to her present timetable or revises it, Ley finds herself in a corner. And that’s just over timing. On the substance of the issue, she is caught between the strong anti net zero lobby within the Coalition and the need to appeal to urban voters and young people, who mostly consider net zero a no brainer.