Scott Morrison is the best person to lead the Liberals to the federal election, Treasurer Josh Frydenberg says.
A series of opinion polls showing the Liberals well behind Labor and the prime minister's personal standing taking a hit has triggered questions about a potential leadership change.
The latest Newspoll published in The Australian on Monday gave Labor a 56-44 two-party-preferred lead - five points higher than just before Malcolm Turnbull lost the leadership in August 2018.
Mr Morrison, who will deliver a major speech to the National Press Club on Tuesday, is weighing up the timing of an election due by late May.
Mr Frydenberg told ABC radio on Monday he believed Mr Morrison would be the first prime minister since John Howard to serve a full term and go to an election.
"Australians know that he's working hard every day to deliver the best health and economic outcome," Mr Frydenberg said.
"He's been subject to some pretty hard personal attacks and obviously that's taken its toll, but I know he is very resilient and I know he's also very focused to work hard for the Australian people."
After the last leadership challenge in 2018, the Liberals changed party room rules to require a two-thirds majority to call a spill.
Labor leader Anthony Albanese declined to comment on the speculation.
"I'll leave it to others, that's not what I'm concerned about ...what I'm concerned about is putting forward a positive agenda," he told 3AW.
In the Newspoll, Mr Morrison's net satisfaction rating plummeted 11 points to -19 while Mr Albanese's rose out of negative figures to zero.
The prime minister has recently taken a lot of heat over the response to the COVID-19 pandemic and an awkward encounter with former Australian of the Year Grace Tame.
Mr Albanese has also narrowed the gap between his rival for preferred prime minister to 43-41 in favour of Mr Morrison, from 45-36 at the last poll.
Health Minister Greg Hunt, who is retiring at the election, said Mr Morrison was best placed "when it comes to keeping Australians safe".
Trade Minister Dan Tehan likened the situation to Rafael Nadal's win in the Australian Open.
"Halfway through the match, in the third set (Nadal) was love-40 down on serve and I think everybody who was watching that tennis game thought he was out for the count," Mr Tehan told Sky.
"But experience, belief and hard work saw that match turn around and saw him holding up that trophy and I think experience, belief and hard work will mean we will put a very good proposition to the Australian people come the election."
Labor frontbencher Ed Husic said the Liberals should be worried about voters' impression of Mr Morrison's leadership.
"I think that's a big issue for them because he is seen as unpopular and it's all of his own making."
