The big four consulting and accounting companies, and other major government contractors would be effectively banned from donating to political parties under a proposal to clean up donations from the Greens.
Senator Larissa Waters, who is the party's spokeswoman for governance issues, wants organisations or individuals who bid for government contracts to be banned from donating to political parties for a set period of time before and after they bid on government tenders.
The second biggest corporate donor to political parties in 2019-20 was Pratt Holdings Pty Ltd, which owns Visy printing. Anthony Pratt's company donated $1.55 million to the Liberal and National parties in 2019-20.
Visy printing was awarded a $10 million grant from Australia's Bushfire Recovery Fund.
Senator Waters acknowledged companies that bid for government contracts regularly, or are part of panel arrangements, would be locked out of donating long-term.
"Certainly that would mean that where there are ongoing rolling tenders, you simply can't donate, you shouldn't be able to buy your way into a government contract, or buy your way into a tender, or buy your way into an environmental approval," she said.
"The four biggest consulting firms - PwC, KPMG, Deloitte, and Ernst & Young - donated $208,000 to the Coalition in the 19/20 financial year. In that same period, they were awarded $600 million in federal government contracts. Some would say that is a pretty good return on investment."
The big four consulting firms were again major donors in 2019-20, donating $485,139 between them to the major parties. Donations were down considerably on the previous year, where the consulting firms donated just over $1 million between them.
The ban on donations from government contractors is just one of many proposals put forward by the Greens, who also want to cap donations at $1000 from any one donor. Senator Waters believes blocking contractors or those seeking government approvals out of the process may have a better chance at success in the Senate.
"We will keep pushing for donations reform, and likewise hope that ultimately, some level of reform is achieved," she said.
"The optimist in me wants to see the Labor Party will back our cap of $1000, the realist in me expects that they won't want such a low cap because they're hooked on those donations."