All four major consultancy firms should stop donating to political parties, the Greens say.
PwC announced on Monday it would no longer directly donate to parties.
The decision covers contributions that are reportable to the Australian Electoral Commission as political donations, including in-kind support such as catering, services and office space.
The company has yet to decide on whether it will continue to pay for memberships to organisations such as the Liberal Party's Australian Business Network and the Federal Labor Business Forum.
Greens senator Barbara Pocock said PwC needed to explain its decision in more detail.
"Will they continue their membership of the business networks run by the major parties?" Senator Pocock said.
"It doesn’t matter what pipeline you use, anyone doing business with the government should not be allowed to give them money, full stop."
She told AAP all of the "big four" consulting firms should stop making cash donations to parties.
"You can’t run a democracy where the business elite are meeting with legislators in the back room and handing over bags of money under the table," she said.
"That stinks and it’s not how you get decisions that are good for the country and in the best interest of the Australian people.”
Senator Pocock said law changes were needed to "break the link between money and politics".
PwC acting chief Kristin Stubbins told the firm's partners in a note on Monday no donations would be made to parties from this financial year.
"Although we have always taken the utmost care to ensure our political donations do not create any real or perceived conflicts of interest, we recognise that doing away with political donations is the best way of ensuring the highest standards of governance," she said.
PwC's new CEO Kevin Burrowes is set to arrive in Sydney early next week.
The company has offloaded its embattled government consultancy arm, but investigations continue into the leaking of sensitive information about proposed federal government tax changes to clients.
