The coalition's primary vote collapsed to 27 per cent, the lowest since the poll began tracking first preferences in 1985, the Newspoll conducted last week and published in The Australian on Monday found.
Labor's primary vote was steady at 36 per cent, giving Prime Minister Anthony Albanese a commanding 58 per cent to 42 per cent two-party-preferred lead - his biggest margin since taking office.
The result comes in the wake of Opposition Leader Sussan Ley's sacking Senator Jacinta Nampijinpa Price from the frontbench, a move that exposed bitter internal divisions over migration, climate change and net-zero policies.
Deputy Liberal leader Ted O'Brien conceded that the past week had been a tough one for the opposition.
"Politics builds big egos, but I tell you, it also gives you some good lessons in humility and we're learning those lessons now," Mr O'Brien told Nine's Today program on Monday.
"But I've got every confidence that we're going to be coming back and we will take a compelling proposition to the Australian people at the election and that's the poll that matters."
Independent Senator Jacqui Lambie suggested that if the coalition's polling doesn't turn around, Ms Ley could face a leadership challenge by Christmas.
The Newspoll found that One Nation appeared to have reaped the rewards of voter dissatisfaction with the coalition, with its primary vote climbing to 10 per cent from 6.4 per cent at the May 3 federal election.
"I think that's always going to be the case when the Liberals are down and out," Senator Lambie said of One Nation's polling.
"They are the camouflage for the far, far right of the Liberal party.
"I'm not sure the way she (Ley) is going right now, with all due respect, is that she's going to last until Christmas time."
The Greens lifted to their primary vote to 13 per cent, while support for independents and other minor parties rose to 14 per cent.
Ms Ley's personal standing took a hit, with her net approval rating sliding to minus 17, with only 32 per cent of voters satisfied with her performance.
She trailed Mr Albanese 31-51 per cent as preferred prime minister.
But Mr Albanese's approval also dipped, falling into negative territory at minus five, though he maintains a solid lead.
While Ms Ley's colleagues have dismissed talk of a leadership challenge, she has sought to reassert control after unveiling a reshuffled frontbench that promoted conservatives Claire Chandler and Simon Kennedy and reinstated James Paterson to her leadership group.
The Newspoll data echo the latest Resolve Political Monitor, published on Monday in Nine newspapers.
It also had the coalition primary vote at 27 per cent - the lowest result since that survey began in 2021.
Labor slipped two points to 35 per cent, while One Nation surged to a record 12 per cent.
On a two-party-preferred basis, Labor leads 55-45, unchanged from the May election.
Resolve logged Mr Albanese's net performance rating at minus one, compared to Ms Ley's plus nine, though he still leads 38-26 per cent as preferred prime minister.
Both polls highlight the ongoing decline in primary vote support for the major parties and a growing appetite for minor parties, such as One Nation and the Greens.
