Former attorney-general Christian Porter has announced he will not contest the next federal election.
Mr Porter announced his resignation with a lengthy post on his Facebook page on Wednesday.
The West Australian MP was first elected to parliament for the seat of Pearce in 2013.
Mr Porter used his resignation statement to attack his critics, saying there was "no limit to what people will say or allege to gain an advantage over a perceived enemy".
"This makes the harshness that can accompany the privilege of representing people harder than ever before," he said.
"But even though I have experienced perhaps more of the harshness of modern politics than most, there are no regrets."
The announcement comes after the 51-year-old was embroiled in scandal for most of 2021.
After the ABC published a story about a historical rape allegation against an unnamed cabinet minister earlier this year, Mr Porter outed himself as the accused, and was then demoted from attorney-general to industry minister.
The MP has strenuously denied the allegations, and settled a defamation case against the national broadcaster.
In September, it was revealed anonymous donors paid for part of Mr Porter's legal fees.
The scandal prompted Mr Porter to tender his resignation from the cabinet, rather than publicly reveal who the donors were.
Mr Porter said he could not guarantee another three years of service to the electorate.
"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," he said.
WA Liberal Party President Richard Wilson paid tribute to Mr Porter following news of the resignation.
"Christian Porter has made an immense contribution to the WA Liberal Party, to the people of Western Australia and to our nation as a whole," he said.
"I would like to to sincerely thank Christian Porter for all he has done for the Liberal Party and wish him all the best as he transitions into life post-politics."
The outgoing MP said he wanted to spend more time out of politics with his family.
"When you are an obsessive compulsive type and entrusted with work that you believe in and that you believe is deeply important, the by-product becomes that people in your life that deserve more from you, especially your family, get much less than they deserve," he said.
"My little boy was born one day before I first became a commonwealth minister. He and his little sister have never known anything but their father's regular absence."
Just last month, Mr Porter denied reports he would be leaving politics.
Mr Wilson said Liberal members would be advised soon about the preselection process for the seat of Pearce.
The Liberals won the electorate in 2019 with a margin of 7.5 per cent, but after a redistribution it is considered a much tighter contest.
Labor has preselected City of Wanneroo mayor Tracey Roberts for the seat.
The election is due to be held by May next year.
Australian Associated Press