Mal Brough's decision to quit federal politics has spared the Turnbull government potential damage from standing a candidate in the crosshairs of a police investigation.
The Liberal Nationals say Brough made up his own mind on Friday, but his decision means the party does not have to dump him before the looming election.
Members of the LNP executive were reportedly concerned about the probe into the Slipper diaries affair, and had held off approving Mr Brough to stand again in the seat of Fisher.
There's strong speculation former Queensland attorney-general Jarrod Bleijie will seek preselection in the Sunshine Coast-based electorate, which Mr Brough won from arch-rival Peter Slipper in 2013.
Labor's candidate, Bill Gissane, has long suspected Mr Bleijie could be his opponent.
"I thought from the outset Jarrod Bleijie would be the most logical replacement as he has the numbers in his branches here but it's up to him if he wants to run," he told AAP.
Mr Bleijie would be the third state LNP MP to seek office in Canberra after Jeff Seeney and John McVeigh, who have nominated for Wide Bay and Groom.
Mr Gissane, who stood for Fisher in 2013, was not surprised Mr Brough opted to quit.
"You could just see the potential of Mal running into the election campaign and having the investigation hanging over his head unresolved," he said.
Mr Brough resigned from the federal ministry in February, having earlier stood aside amid a police investigation into his alleged role in the Peter Slipper-James Ashby affair.
The investigation is looking into whether he asked Mr Ashby, a former staffer of Mr Slipper, to copy the former Speaker's diary.
He has denied any wrongdoing, despite telling the Nine Network in 2015 he asked Mr Ashby to procure copies of the diary.
Mr Ashby says MP Wyatt Roy told him to make a copy of the diary after speaking to frontbencher Christopher Pyne.
The Australian Federal Police says their investigation is ongoing.
Federal shadow attorney-general Mark Dreyfus said Mr Brough's decision was one Prime Minister Malcolm Turnbull should have made months ago, but was by no means the end of the saga.
"Christopher Pyne and Wyatt Roy have their fingerprints all over this and they're yet to give a full explanation. Their stories just don't add up," he said.
Mr Brough's resignation came as the LNP state executive were to meet and discuss his Fisher candidacy.
The party insisted Mr Brough was not tipped off about the executive's views before his announcement.
"I thank the people of Fisher for their support at the last election and the trust they placed in me to be their voice in Canberra," Mr Brough said in a statement.
"It has been a privilege and honour to represent this generous community."
Mr Turnbull said Mr Brough was a "tireless advocate for local infrastructure and services" and would be missed.
The LNP will open nominations for Fisher on Monday.
