Labor has accused the prime minister of running a protection racket for a Liberal MP facing questions about her ties to the Chinese government.
As allegations of Chinese foreign interference swirl around federal parliament, opposition senator Penny Wong is demanding Gladys Liu explain her connection to various Beijing-linked organisations.
"Gladys Liu has refused to give a statement to the parliament. She is being protected from doing so by Mr Morrison," Senator Wong told reporters in Canberra on Tuesday.
Ms Liu, a first-term MP for the Melbourne seat of Chisholm, faced scrutiny earlier this year over previous links to Chinese Communist Party propaganda groups.
The simmering issue has gathered steam again in recent days after allegations emerged that China tried to plant a spy in Australia's parliament.
Australian Associated Press