Voters have been promised a chance for renewal as Scott Morrison bows out of politics, with friends and a former rival reflecting on his turbulent time as prime minister.
Mr Morrison will depart federal parliament at the end of February for a job in the private sector.
Anthony Albanese, who defeated Mr Morrison at the 2022 election, was among the first to wish him well.
"It's a great honour to have been prime minister of Australia ... I thank him for his service," Mr Albanese said on Wednesday.
"I wish him and Jenny and his family all the very best."
Mr Morrison entered parliament in 2007 and served as prime minister for almost four years.
His initial response to COVID-19 won plaudits but his government was later condemned for its slow vaccine rollout and shortage of rapid antigen tests.
It was later revealed Mr Morrison secretly appointed himself to several portfolios throughout the pandemic, giving himself power to overrule the decisions of cabinet colleagues.
He was widely criticised for holidaying in Hawaii during the Black Summer bushfires and for his handling of rape allegations by Brittany Higgins.
Mr Morrison was also accused of lying by the French president and of misleading cabinet by the robodebt royal commission.
Simon Birmingham, who served in Mr Morrison's ministry, said he got the big calls right.
"If any of us are without fault then, then by all means step forward," Senator Birmingham said.
"But ultimately, when you look at the big calls and the things that impacted the lives of the vast majority of Australians and will impact them in terms of their security and prosperity into the future, Scott Morrison absolutely got it right."
Mr Morrison's exit from politics will set up another federal by-election early this year, with Senator Birmingham describing the contest as "an opportunity for renewal and regeneration".
A strong field of candidates are in the race to replace the former prime minister in his south Sydney seat of Cook.
Sutherland Shire Mayor Carmelo Pesce and former Bennelong candidate Simon Kennedy are expected to throw their hats in the ring.
State MP Eleni Petinos and Gwen Cherne, an advocate for families of veterans, have also been suggested by Liberal sources as likely candidates.
NSW opposition leader and Cronulla local Mark Speakman has ruled himself out of the race.
"I'm here to fight the good fight in NSW," he said.
Mr Morrison holds the southern Sydney seat by a safe margin of 12 per cent.
The by-election, which is not expected to be held until at least April, will follow that for Dunkley in Victoria on March 2.
The latter was triggered by the death of Labor MP Peta Murphy and is expected to be a much closer contest.
Liberal Party legend John Howard was a mentor to Mr Morrison and said despite the criticism received as prime minister, he achieved success at home and abroad.
"It was never my privilege to serve in the parliament with Scott Morrison, but I admired his leadership, his commitment to Liberal principles and the high integrity he brought to the prime ministership of this country," Mr Howard said.
