Defence Minister Peter Dutton says former attorney-general Christian Porter has been unfairly hounded out of politics.

The MP for the West Australian seat of Pearce will retire from parliament at the election following a scandal-plagued year in which he was accused of a historical rape he strenuously denies.

“He was probably the finest lawyer I’ve met,” Mr Dutton told 2GB of the former attorney-general on Thursday.

“He’s been hounded out of politics in a very unfair and unjust way. But that’s the nature of public life in the year 2021, unfortunately.”

Mr Dutton said social media played a big part in allowing sledging of politicians.

Mr Porter, who once held prime ministerial aspirations, hit out at the “harshness of modern politics” in announcing his resignation on Facebook on Wednesday.

He was demoted to industry minister over the historical rape allegation.

He then quit cabinet altogether after admitting to using anonymous donors to pay for his defamation case against the ABC over its story about the allegation.

Health Minister Greg Hunt is expected to announce his retirement on Thursday after 20 years representing the Victorian seat of Flinders.

Treasurer Josh Frydenberg described the health minister’s departure as “a big loss for me and his electorate and the country and for the coalition”.

He wanted to see women pre-selected to run for the Liberals in Flinders and Pearce.

“There are good female candidates who will be in the field for preselection. But, ultimately, those decisions will be in the hands of the preselectors,” Mr Frydenberg told the Nine Network.

It’s been a messy sitting fortnight for the government, with nine coalition MPs and senators crossing the floor on a variety of issues.

Thursday is the final day of parliament for the year.

An election is expected to be held in May.

– AAP