Thousands of people have turned out across the country to call on the Queensland and Commonwealth governments to stop the proposed Adani coal mine.
Hundreds of demonstrators gathered outside Parliament House in Canberra to voice their opposition to the Carmichael mine as dozens of similar rallies took place across Australia on Saturday.
"The mine is just going to ruin everything - the water, the reef, the farming land - and also we're lending them $1 billion and I cannot believe we can't spend that money on jobs in other areas like renewables," Michele Smith told AAP in Canberra.
Fellow protester Kathy Kituai is sceptical about what the state and federal governments stand to gain from the "insane" project, while Lois McRae is worried about the irreversible damage it may cause.
"It is ludicrous to propose this mine and it has got to be abandoned," Ms McRae told AAP.
The national rallies come as new polling shows more than half of Australians oppose the central Queensland mine.
Two-thirds of people also believe the Queensland government should veto a proposed $1 billion Commonwealth loan for a rail line to the Carmichael mine.
Major rallies took place at Bondi Beach, Brisbane, Port Douglas and Carlton North, with dozens of events held across each state and territory.
Those gathered in Canberra waved placards and chanted slogans before heading off on a march, while people in other locations created human "Stop Adani" signs.
Almost 2200 people were quizzed in the ReachTel poll this week.
Respondents were told Adani wanted to build a new coal mine in Queensland, which the Indian company said would create local jobs.
They were also told concerns had been raised about the company's corporate track record and the environmental impact of the mine, before being asked if they supported or opposed the project going ahead.
A clear majority of people (55.5 per cent) either opposed or strongly opposed the mine, while 26.1 per cent said they supported or strongly supported it.
Almost one in five (18.4 per cent) were undecided.
Support was highest among Australian Conservatives, Liberal and One Nation voters, while Greens, Labor and Nationals voters were most keenly opposed.
An ABC Four Corners investigation this week aired allegations of bribery, corruption, tax evasion and money laundering by Adani-linked companies.
Those polled were also told Queensland Premier Annastacia Palaszczuk made an election commitment that Labor would not spend public funds on Adani's private rail line for their coal mine.
People were then asked if the Queensland government should keep its promise and use its power to veto a $1 billion Commonwealth loan to Adani for the rail line.
Two-thirds of respondents (65.8 per cent) said they should veto the loan, while 17.7 per cent said they should not, with 16.5 per cent undecided.
The Stop Adani Alliance, which is organising the national rallies, is made up of 31 organisations.
Its membership has doubled since it launched in March, while more than 160 groups have formed in that time.