ASIO director-general Mike Burgess confirmed on Sunday the agency was investigating an alleged plot to plant a Chinese spy in the Australian parliament.

Nine's 60 Minutes, The Age and The Sydney Morning Herald aired allegations that Chinese operators offered Liberal Party member Nick Zhao $1 million to run for the seat of Chisholm. Mr Zhao, who alerted ASIO to the approach, was found dead in a Melbourne hotel room in March.

The case has reignited concern about Australia's political donations laws.

Greens leader Richard Di Natale said wealthy countries and individuals would continue to try to use donations to "subvert our democracy" unless political donations were reformed.

"The fact is that if we banned political donations and introduced election spending caps, then no foreign entity or vested interest would be able to buy their way into parliament," Senator Di Natale said.

Labor senator Don Farrell planned to introduce two private senators bills on Tuesday to reform political donations.

One would lower the disclosure threshold from the current $14,000 to $1000, while the other would require recipients to disclose donations within seven days.

There is already a parliamentary inquiry running into a separate bill from Centre Alliance MP Rebekha Sharkie that would force parties to report political donations within five business days.

Liberal federal director Andrew Hirst told that inquiry real-time donations would be too onerous for the largely volunteer run organisation to maintain.

"It has been the long-standing position of the Liberal party that Australian democracy is best served by a legislative framework for political party funding that is fair to all parties, is not unduly onerous or party administration and takes adequate account of the role of third parties, such as trade unions and activist groups," Mr Hirst wrote.

"The Liberal party does not support changes to these arrangements that would unnecessarily add to the already considerable administrative and compliance burdens placed on political parties. The Liberal party does not support changes which fail to recognise that political parties are broad-based organisations with large volunteer wings and limited resources.

"The Liberal party supports the existing funding and financial disclosure regime, including the arrangements for the lodgment and publication of annual returns, which have been in place under successive governments."

However the Greens also rejected the Centre Alliance bill, as it did not lower the current cap or allow for the additional costs involved in compliance.

Instead, the party said a cap of $3000 should be imposed on all donations, with a disclosure threshold of $1000, in its submission to the inquiry.

The government should try to harmonise political donations laws in all states and territories through COAG, the Greens also said.