Addressing the National Press Club, Climate 200 convenor Simon Holmes a Court said his organisation had received more than 10,000 donations to back climate-conscious candidates ahead of the imminent federal election, where independents could wrestle the balance of power.
But he warned the money would "pale into insignificance" compared to major parties, noting Independent MP Zali Steggall was outspent by a two-to-one ratio when she ousted former prime minister Tony Abbott at the 2019 election.
"The political parties are Goliaths and they have rigged the game," he said.
"Hacking at the branches hasn't been working, we have to strike at the root … (that) means getting people into parliament who are strong, independent, and ready to hold government accountable."
He challenged major parties to lower the donation disclosure threshold to $1000 and require real-time disclosure.
Quizzed if his organisation was any different to a political party, Mr Holmes a Court said he had no sway on policy positions for the candidates.
"Multiple independents came to us and said even one string is too many, it must be no strings attached," he said.
"Our relationship with the candidates – we make a donation, if they ask us, if they are looking for advice on who they can talk to, we will pass that on. But we don't have any agreement at all with the candidates, they are strictly independent and that is of critical importance to them ... because otherwise it wouldn't be independence."
He also lashed the government's climate policies as an "embarrassment" and "a joke nobody finds funny", and suggested it was spending millions of dollars each month on a "positive energy greenwashing campaign".
"Telling us that Australia is doing great on emissions reduction (is) a bald-faced lie," he said.
"This is taxpayer-funded election advertising, disguised as information. The truth … real emissions have fallen by less than one per cent between 2013 and 2020."
He said internal polling had many of the candidates in "very competitive positions".
"These candidates don't need to go into politics to be successful because they are already successful," he said.
"They are business owners, doctors, lawyers, journalists and athletes. They are in it for the right reasons."
Signalling the candidates would prioritise action regarding climate change, an integrity commission and treatment of women, Mr Holmes a Court said independents tackle legislation major parties found "too hot to handle".
Dave Sharma, one of the Liberal MPs being challenged, told Sky the group had all the hallmarks of a political party because they wore the same colours, stood on the same platform and had a spokesman in Mr Holmes a Court.
"If it looks like a political party, if it acts like a political party, if it feels like a political party I would suggest it is a political party," he said.
Assistant minister Amanda Stoker said independents should be renamed the "unaccountables".
"The major parties may not be perfect, and they do make mistakes from time to time, but at least you know what you're getting. And you never know that with an independent," she said.