Labor MP and chief opposition whip Chris Hayes has announced he will retire at the next federal election, sparking a hot contest for his safe seat.
Mr Hayes entered parliament following a by-election for the electorate of Werriwa in 2005, succeeding former party leader Mark Latham.
He moved to the western Sydney seat of Fowler in 2010 and has comfortably held it ever since.
The long-serving politician is far better known for his work behind the scenes than in the public gaze.
But he attracted headlines late last year after collapsing during a speech in parliament.
Mr Hayes said health issues had contributed to his decision.
"After 16 years I think it is time to pull the pin," he told reporters in Canberra on Wednesday.
"I feel that I am slowing down and I've always thought being a member of parliament is being here while you're making a contribution.
"If you start resting on the oars, well I think if you truly believe why you're here in the first place is to make a difference for the better, you know in yourself it's time to call it a day."
He will serve out the rest of the term but will not recontest the next election.
Mr Hayes said he had a young woman in mind who would be ideal to succeed him as the member for Fowler, urging the community lawyer of Vietnamese heritage to run for pre-selection.
He said the woman, whose parents came to Australia as refugees, represented the face and aspirations of what was one of the most diverse communities in the country.
However, the race for the prized seat is likely to be fiercely contested.
