Donations to Australia's two major political parties are dominated by "large and opaque" sources, sparking calls for a real-time disclosure scheme and caps.
About 42 per cent of Liberal donations and 33 per cent of Labor donations since 1998/99 have come from associated entities, the Centre for Public Integrity says.
Associated entities can include such things as 500 clubs, think tanks, registered clubs, service companies, trade unions and corporate party members.
The centre has flagged concerns about hard-to-trace information regarding the source of this money, with disclosures from the groups revealing only limited information.
Between 1998/99 and 2019/20, the centre's analysis shows, federal Labor received a total of $564.25 million in donations.
Of this funding, $179.56 million came from associated entities while $160.24 million, or nearly 30 per cent, came from associated trade unions.
The coalition received cumulative donations worth $499.16 million, of which $194.98 million came from associated entities.
"Funding of our political parties is dominated by large and opaque donations," Centre for Public Integrity chair and former NSW Court of Appeal judge Anthony Whealy said.
"Private money is pouring into our democracy at increasing rates. The last election set the record for the most donations in any federal election."
The coalition received another $53.13 million from the property and construction industry, amounting to more than 11 per cent of overall donations over more than 20 years.
Its third-largest source was individuals, who contributed $43.35 million or about nine per cent of overall donations.
In comparison, individual donations to Labor over that time-frame amounted to $14.36 million.
More than 21 per cent of total Labor donations came from 46 donors, while 22 per cent of coalition donations originated from 51 donors.
The resources industry has given the United Australia Party about $128 million, while donating more than $21 million to the coalition and nearly $5.5 million to Labor.
Mr Whealy called for campaign spending caps to stop the "fundraising arms race" and donation caps to curb the influence of millionaire donors as well as real-time disclosure of donations worth more than $1000.
The Greens have released a plan to adopt the $1000 cap, and ban all donations from the mining and resources sector.
The party also wants to see a five-year ban on resources ministers and advisors heading to the fossil fuel industry after parliament, as well as a public register of meetings between ministers and mining lobbyists.
Centre for Public Integrity data shows the Greens receiving about $20 million worth of donations since 1998/99, with more than 78 per cent coming from individuals.
The Australian Electoral Commission will on Tuesday publish 2020/21 financial disclosure returns for political parties, associated entities, donors and significant third parties.
