By James Massola and Political Correspondent
Hundreds of years of experience will be lost by the time the 2016 election is held, with cabinet ministers, party leaders, junior ministers, a former speaker and backbenchers on their way out the door.
On Friday former veterans' affairs minister Michael Ronaldson became the latest to announce he was quitting, creating a vacancy in the Victorian Liberal Party's Senate team. He will be the 12th MP to leave at or before the election.
The retirements represent a significant changing of the guard in federal politics, and more MPs are expected to follow suit in the coming months.
In all, 206 years of experience will be lost after the retirement of Labor MPs Kelvin Thomson, Anna Burke, Bernie Ripoll, Jan McLucas and Alan Griffin; Liberals Ronaldson, Bruce Billson, Andrew Southcott and Joe Hockey; Nationals MP Bruce Scott; and the Greens' Christine Milne and Penny Wright.
Three more MPs that had been expected to exit politics after a spectacularly awful 2015 in which their careers crashed and burnt – former prime minister Tony Abbott, former defence minister Kevin Andrews and former speaker Bronwyn Bishop – are now expected to stay in politics beyond the next election.
Mr Abbott has delayed his decision on his future until next year, and has made a series of deliberately provocative statements on national security and Islam since losing the top job, fuelling speculation that he intends to mount a Kevin Rudd-style political insurgency.
Nationals leader Warren Truss is widely expected to announce his retirement in the first quarter of next year, while there is also chatter in National Party ranks that Senate leader Nigel Scullion and MP John Cobb could also exit.
Liberal Philip Ruddock - who is the longest serving MP and father of the house - is also being closely watched by ambitious would-be MPs in and around his plum seat of Berowra. Meanwhile, Liberal MP Ian Macfarlane is tipped to retire after his his plan to defect to the National Party was blocked.
There is speculation that Labor MPs Jill Hall and Laurie Ferguson may also quit their Sydney-based seats, though that is unlikely to be confirmed until after a redistribution of NSW electoral boundaries is finalised early in 2016.
In the exit lounge: leaving at or before the 2016 election
Kelvin Thomson (Labor) - 20 years service
Anna Burke (Labor) - 18 years
Bernie Ripoll (Labor) - 18 years
Jan McLucas (Labor) - 17 years
Alan Griffin (Labor) - 23 years
Michael Ronaldson (Liberal) - 23 years
Bruce Billson (Liberal) - 18 years
Andrew Southcott (Liberal) – 20 years
Joe Hockey (Liberal) - 19 years
Bruce Scott (LNP) – 26 years
Christine Milne (Greens) -10 years
Penny Wright (Greens) – 4 years
Total: 206 years of experience