Christian Porter has resigned as the federal minister for industry after failing to explain who was behind an anonymous donation to pay for his court case.
Prime Minister Scott Morrison told reporters in Sydney on Sunday he had accepted Mr Porter's resignation and had appointed Energy Minister Angus Taylor to act in his role.
"His actions have been about upholding the standards," Mr Morrison said.
A "blind trust" paid the settlement for an outstanding court case of Mr Porter's stemming from when he sued the ABC in March. The legal action was over a story that revealed a now-deceased woman's historical rape allegation against a cabinet minister.
Mr Porter emphatically denied the allegation and the case was settled before trial.
Mr Morrison said that in discussion with Mr Porter over the last few days, the minister was unable to practically provide further information because of the nature of the donation arrangements.
"He has this afternoon taken the appropriate course of action to uphold those standards by tendering his resignation as a minister," Mr Morrison said.
"I expect my ministers, all of them, and myself, to uphold the ministerial standards and to act in accordance with those ministerial standards."
Mr Porter will now return to the backbench to serve as the member for the Western Australian seat of Pearce.
Mr Morrison thanked him for his time in the ministry, which included being attorney-general and leader of the House of Representatives.
In a statement, Mr Porter said he understood the questions raised in the media about the financial arrangements to help fund the now-settled litigation.
"But I consider that I have provided the information required under the Members' Register of Interests. I also considered that the additional disclosures I provided under the Ministerial Standards were in accordance with its additional requirements," he said.
"However, after discussing the matter with the Prime Minister I accept that any uncertainty on this point provides a very unhelpful distraction for the Government in its work."
But Opposition Leader Anthony Albanese said Mr Porter still had many questions to answer as a member of parliament and was in breach of his obligations.
"He needs to answer where this money came from," Mr Albanese told reporters in Sydney.
"Members of parliament, as well as ministers, just can't accept money from anonymous donors for a private legal matter. He is not fit to be a member of parliament."
Australian Associated Press