Mr Abbott is considered to be the frontrunner in any challenge, but there is also strong support for Treasury spokesman Joe Hockey.
Mr Hockey has said he will contest the leadership only if it is vacated by Mr Turnbull, who was digging in last night, saying he would remain Liberal leader until the party removed him.
Mr Turnbull believes that abandoning support for the compromise Carbon Pollution Reduction Scheme would be fatal for the Coalition’s electoral prospects.
According to the Newspoll analysis, support for the government’s emissions trading scheme legislation is overwhelming among Coalition voters in metropolitan areas. Newspoll shows that 63 per cent of Coalition voters in the cities believe the government’s bill should be passed, while only 28 per cent think it should be opposed.
If one in 10 of those voters changed sides because of a Coalition decision to block action on climate change, it would cost the Liberal Party the 20 metropolitan seats that it holds with margins of less than 6.5 per cent.
These findings are consistent with the Liberal Party’s internal research in marginal seats, which shows that between 75 and 80 per cent of swinging voters favour action on climate change.
Senior party officials say the research shows a triumph by climate change sceptics would be “the death of the party”.
Newspoll chief executive Martin O’Shannessy says the most worrying finding for the Coalition is that its voters aged 18 to 34 favour the government’s legislation by a margin of almost five to one. The Newspoll survey, taken in mid-September, showed that 75 per cent of Coalition voters in this age group backed the bill, while only 17 per cent were opposed.
“It was a tremendous swing in that age group that put most of the energy behind the swing to Labor in 2007,” Mr O’Shannessy said, noting that the same age group had also been important in the success of former prime minister John Howard.
“These people aren’t rusted on to the Coalition, even though they say they’re Coalition voters. They are clearly at risk.”
The Newspoll analysis shows that Coalition seats are not safe in rural areas either. A clear, though much smaller, majority is also in favour of the government’s bill.
In rural seats, Newspoll found that 41 per cent of Coalition voters were opposed to the government’s emissions trading scheme bill while 50 per cent were in favour.
Whatever the Coalition does will lose votes in rural seats, but opposition to the climate change legislation would lose it more.
The Liberal Party’s own research shows the strongest opposition to the government’s bill is in the bedrock 35 per cent of the electorate that is its core support.
Many of these conservative voters share Senator Minchin’s belief that there is no human-induced change to climate.
These are the voters who have been inundating MPs’ offices with emails and phone calls, urging them to block the legislation.
However, the party’s analysis of voters who supported the Coalition in 2007 but previously voted Labor, and former Coalition supporters who voted for a change of government at the last election, shows they massively favour action on climate change.
Election analyst Malcolm Mackerras said the Newspoll analysis is consistent with his own research, suggesting the Coalition would lose up to 20 seats, taking Labor’s majority from 26 to more than 40 seats.
Mr Mackerras said he believed high-profile Liberals such as Mr Hockey, Mr Andrews and Mr Robb had enough local support to retain their seats.
However, if Mr Turnbull vacated his eastern Sydney seat of Wentworth at the next election, it would fall to Labor.
Mr Mackerras said the leadership infighting would cost the Coalition severely. “The instability is a greater reason for them losing votes than their climate change position, but both are bad losers.”
Labor had passed up an opportunity by deciding not to contest the December 5 by-election in the Melbourne seat of Higgins, being vacated by former treasurer Peter Costello, Mr Mackerras said.