He is expected to remain in the health portfolio until election day,which would help Mr Morrison avoid appointing a replacement during the vaccine booster program and dealing with new coronavirus variants.

The father-of-two,who was first elected in November 2001,is one of only three Liberal MPs,along with Prime Minister Scott Morrison and Home Affairs Minister Peter Dutton,to have served in federal cabinet since the Coalition came to power in September 2013. He has held the health portfolio since January 2017.

Federal Liberal MP Jason Falinski said the retirement of prominent MPs was simply “the natural process of renewal of the Parliament”.

“It’s not a bad thing... I think it’s a positive thing that you’ll have renewal of the Parliament on both sides,so that’s what’s going to occur,” Mr Falinski told ABC’sAfternoon Briefing.

Mr Porter was attorney-general from 2017 until March 2021,when Prime Minister Scott Morrison reshuffled his cabinet to make him the Industry and Science minister. He was moved after Mr Morrison received legal advice questioning whether Mr Porter could remain in the key legal role while he was suing the ABC for defamation.

Mr Porter later resigned from cabinet entirely rather than reveal the names ofthe anonymous donors who funded his legal claims.

Mr Porter sued the ABC over a story he said accused him of raping a debating teammate in 1988. Mr Porter vehemently denied the story.

The case was settled,with the ABC appending a note to its story saying it did not intend to suggest Mr Porter “had committed the criminal offences alleged” and regretted some readers had interpreted it that way.

However,the ABC did not retract the story or apologise. It made a $100,000 contribution to Mr Porter’s legal fees for mediation and related costs,though his total bill was likely many times that given the ABC spent $780,000 to defend the matter,including the payment.

“There are few,if any,constants left in modern politics. Perhaps the only certainty now is that there appears to be no limit to what some will say or allege or do to gain an advantage over a perceived enemy,” Mr Porter said in his farewell post.

“This makes the harshness that can accompany the privilege of representing people,harder than ever before. But even though I have experienced perhaps more of the harshness of modern politics than most,there are no regrets.”

Mr Porter said he realised he could no longer guarantee his commitment to serving as the member for Pearce beyond the 2022 election.

“Before each election I have always asked myself whether I could absolutely guarantee another three years of total commitment to the electorate because people deserve that commitment,free of any reservations,” he said.

“After a long time giving everything I could to the people of Pearce it’s now time to give more of what is left to those around me whose love has been unconditional.”

Former prime minister Tony Abbott said ina social media post he was disappointed Mr Porter was retiring “after being effectively hounded from the ministry on the basis of decades-old and unprovable allegations”.

“It’s sad and wrong that a capable person’s contribution can be curtailed in this way,” he said.

Former Liberal candidate for the seat of Fremantle in the March state election Miquela Riley confirmed she intended to run for preselection to replace Mr Porter. The hard campaigning Navy lieutenant impressed party pundits during her campaign and she has the backing of the Liberal Party’s wealthy Perth western suburbs faction.

“I think I’ve got what it takes to represent Pearce and the electorate of Pearce and if I’m afforded that opportunity that’s exactly what I’ll do,” she said.

“I wouldn’t be putting my hat in the ring if I didn’t think that I had what it took to keep that seat.”

Former Liberal WA Premier Colin Barnett,who elevated Mr Porter to the state attorney-general and treasurer portfolios,said he was sad to see him leave politics.

“I think he would have become a prime minister had he stayed in the long term. So we’ve lost a potential West Australian Prime Minister,which would have been the second since John Curtin during the war,” he said.

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