Students have joined politicians and health professionals outside Scott Morrison's Sydney prime ministerial residence to demand action on climate change.
Climate protesters have vowed to camp outside the prime minister's Sydney residence, Kirribilli House, until he returns from holidays.
"The tent city isn't moving until he shows up," organiser Ambrose Hayes told the crowd. "Many of us are prepared to stay overnight."
"Our direct message to Scott Morrison is for him to come home ... even though he's entitled to a holiday, it shouldn't be at a time where Australia is in crisis," said the 14-year-old.
Demonstrators gathered outside Kirribilli House on Thursday morning demanding urgent action amid unprecedented bushfires, with one doctor declaring climate change the greatest health crisis of the century.
The prime minister is currently on a family holiday, with rumours he is in Hawaii.
Riot squad officers were at the scene of the Kirribilli House protest, which took place on Thursday with the smell of bushfires heavy in the air.
The demonstrators, some of whom wore Hawaiian shirts, carried placards asking "ScoMo where the bloody hell are ya?" and "When do our firefighters get a holiday?"
The crowd sang an altered version of popular Christmas carols, titled "We Wish You a Coal-Free Future" and "Cool Down the World".
They called on the federal government to take immediate action on climate change and urged no new coal and gas projects, a transition to 100 per cent renewables and funding for affected fossil fuel workers.
Dr Kim Loo, who works in Sydney's north-west, said poorer people were bearing the brunt of the effects of climate change.
"It is negligent not to do anything about mitigation or adaptation. It is criminal to continue mining, burning, exporting oil, coal and gas because it's fuelling the crisis," Dr Loo told the crowd.
"And this is the greatest crisis to our health in the 21st century."
SBS News has contacted the prime minister's office for comment.
On Wednesday, Acting Prime Minister Michael McCormack defended the timing of Mr Morrison's break.
"Everybody deserves a holiday," Mr McCormack told reporters. "Everybody deserves a break, he worked hard this year, achieved great things for Australia."
Opposition Leader Anthony Albanese also did not have a problem with Mr Morrison taking a few days off.
"I have many criticisms of Scott Morrison. One isn't when he chooses to go on leave with his family," Mr Albanese said on Wednesday.
"People are entitled to have leave and that's a matter for him when he takes it."
Timing of holiday 'bizarre'
But protesters labelled the prime minister cowardly for leaving the country.
Derek Bolton said it was bizarre.
"Most prime ministers would have the sense not to go away on holiday when a country is in a crisis like this."
He has been active in the climate movement for 12 years and said the involvement of so many young people was inspiring.
"When I went to the big one in Sydney a year or so back I was moved to tears, it was the most heartening thing I'd seen in my entire experience in this process."
Sonia Freiburg urged Mr Morrison to return.
"It's his job to look after Australia and he should be here to do that."
Inez Russel sat inside one of the tents set up outside Kirribilli House, but wasn't sure if she would stay until the prime minister returned.
"He's abandoning us in a time of national crisis and that's not what a leader does, that's what a coward does," the 17-year-old said.
Additional reporting by AAP