Labor Party stalwart Simon Crean will quit politics at the next election, saying his departure is an opportunity for "renewal".

The former ALP leader says, after 23 years in Federal Parliament and 40 years in public life, "it's time" for him to leave.

"I came in (during) the ascendancy of Gough (Whitlam), it was time then and I think it's time now for me," he said.

"If I stood again I would be 67 by the time the next election came around."

Mr Crean was opposition leader from late 2001 for two years. He was elected as the member for the Victorian seat of Hotham in 1990.

Before entering Parliament, Mr Crean was a senior officer of the ACTU, including president from 1985 to 1990.

As vice-president in 1983 he played a central role in setting up the Accord with the Hawke Labor government.

"I think the best thing I did was being part of the Accord mechanism that changed this country," he said.

"That set it up for 22 consecutive years of economic growth."

He has cited "loyalty" as an important personal quality.

"You've got to give it to get it. I've given it - haven't always got it," he said, saying he has always acted for the good of the party.

"I didn't come into politics for personal advancement, I came in to change things, to make a difference, and to use the strength of the party structure, the collective if you like, to make those changes."

Mr Crean said he started thinking seriously about quitting after his failed attempt to trigger a leadership ballot in March.

"It would've been a lot harder to have done it then... after the ballot that wasn't," he said.

"Now that we had a ballot that was, and the result is as it has been, I thought it appropriate to call it a day."

He says last week's leadership ballot which thrust Kevin Rudd back into the Lodge has vindicated his actions.

"I feel vindicated in the sense that it was important to make the call and to show the lead," he said.

"That's now happened, it's happened. We're now in a stronger position."

Crean doubts if Gillard has forgiven him

He says he hopes the party has been left in "good shape" and believes Labor can win the next election.

"This is the opportunity for regeneration, renewal," he said.

He says the past three years of bitter leadership rivalries in the Parliament have been the low point in his political career and should stand as an important lesson to the next generation of Labor MPs.

Simon Crean was elected to Parliament in 1990. ( AAP )

And, despite calling for Julia Gillard to stand aside as prime minister, he says he bears no animosity towards her though he believes she has not yet forgiven him.

"Oh no, I think that'll take a while I suspect. I really haven't had a conversation with her," he said.

"I think she is a wonderful person. I've known her over a number of years. I've mentored her."

Mr Crean says he was offered a spot in the new Rudd ministry and was willing to serve but only until the election.

"I left him essentially the option to use the position to regenerate, or if he needed me to plug a gap until the election I was more than happy to serve in that regard," he said.

"It was only last night that he came back to me and said he wanted to exercise the former of those two points."

Leaders offer tributes to Labor stalwart

Mr Rudd says Mr Crean has made a "fantastic" contribution.

"I would also like to acknowledge here publicly as Prime Minister of Australia how much I value his work over the years," he said.

"He has been an extraordinary leader in our movement for a long period of time."

Opposition Leader Tony Abbott said his departure from public life was "sad for our country".

"I think it's sad for Labor, I think it's sad for our country, that Simon Crean is apparently not going to be in the ministry," he said.

"I want to pay tribute to Simon Crean. He is a decent, honourable Labor man. He is a person who has achieved a lot for his party and our country."

Mr Crean says he will leave politics with "mixed emotions".

"I expect to be a bit liberated, but it's the closure of a fairly long time in politics," he said.

"There's been a Crean in politics or public life for almost 70 years in this country, and Creans have served in every Labor Cabinet in that time."

His father Frank was a minister in the Whitlam government and his brother David was a minister in the state Labor government in Tasmania.