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Outgoing treasurer Peter Costello says he will step back from politics following last night's election loss and will not stand for the leadership or deputy leadership of the Liberal Party.
Mr Costello said he had decided not to stand for the position of opposition leader, but would continue to serve as the member for the Melbourne seat of Higgins.
"I've discussed this with my family and my wife Tanya, who is here with me today, and we have decided that in fact the time has come for me to open a new chapter in my life," Mr Costello told reporters in Melbourne.
"I will be looking to build a career post-politics in the commercial world.
"As a consequence of that, I will not seek nor will I accept the leadership or deputy leadership of the Liberal Party.
"I want to spend more time with my family and do something for them."
Mr Costello said he had told outgoing prime minister John Howard of his intentions last night.
He said he had thought the Liberal Party was ready for a "generational" change of leadership midway through last year.
But when Mr Howard opted to stay on in the top job, Mr Costello said he had decided that if the coalition lost the election he would not seek the leadership.
"Last year I argued the case for generational change and I put that view to my colleagues, a majority of whom did not agree," Mr Costello said.
"My thinking then was that if we won the election there would be generational change after the election if we won, but if we lost I thought it would be time for a new generation.
"I spoke to the prime minister about this matter last night."
Mr Costello said it was time for change in the party.
"I believe in generational change in the Liberal Party," he told reporters.
Mr Costello said it was time for a new generation to take the fight to Prime Minister-elect Kevin Rudd.
"I do believe that it is time for the young people of talent and ability, of whom there are many, to be given their go in the Liberal party just as I was given my go in the early 1990s.
"I've been re-elected as the member for Higgins and I thank the people of Higgins for the trust that they have shown in me.
"I will continue to serve my constituents and in serving my constituents I hope that I will have a role to play perhaps mentoring some of the newer MPs."
Mr Costello would not explicitly say if he thought the outcome of the federal election would have been different if he was leading the Liberal party.
But he pointed out that he had been pushing for generational change.
"Look, I argued the case, you know what my view was," he said.
"I was very upfront about it, I put it publicly, in this room and many other rooms.
"A majority didn't agree, that's it."
Mr Costello said he had put the case for generational change to the Liberal party strongly and personally.
"If the majority doesn't agree with you, that's it, I accepted their decision - I have to accept their decision. That's life."
Mr Costello said he was tired because he had been campaigning hard and had a late night followed by an early morning.
But he also felt concerned.
"I feel concerned for our country, I do think that there are a couple of things that if they are done could badly affect its prospects," he said.
One of the things was Labor raiding the Future Fund, which he described as "one of the worse pieces of public policy that has ever been put forward".
Mr Costello said people would judge his political career on results.
"I've always been in politics to do what I can for Australia and it's people and I've done the best that I can over the past 11-and-a-half years and people will judge me by my results," he said.
Mr Costello said it was up to the people in the party to nominate themselves for the leadership role.
"I will have a vote and now it's up to the candidate to put themselves forward, I will carefully consider my vote in that ballot."
Mr Costello refused to discuss likely candidates for the job but said it was time for generational change.
"The political cycle goes in generations in my view, a period of testing in opposition followed by the opportunity to govern.
"I think we have some really good people in the next generation, I think it's up to the Liberal Party to give them a go.
"You gave me a go and now's the time to give some others a go.
"I don't want to get into names because I will leave somebody out and that would be a terrible tragedy."
Mr Costello said a Sensis survey of small business last week reported the biggest fall in business confidence ever measured.
"That drop in confidence was because of a change in government," he said.
"Small business will be worried and I am worried for small business.
"I am a great believer in small business. Small business creates the jobs. You have go to give them the go.
"The idea that union officials are going to start knocking on small business doors will strike fear and terror into their hearts. "
Mr Costello said opinion polls showed Labor took the lead last year and that lead hardly ever varied.
"My assessment was that it wasn't particular policies that the electorate was reacting to.
"There was just a segment of the electorate that had decided it was time to change the government and it wouldn't be a big risk," he said.
"And that was enough really. We were we coming back in the last couple of days - it's hard to tell.
"There were some polls that said we were because there were people at the end who were starting to worry about the risk, which I believe was a real risk by the way.
"The events of the last couple of days just deprived us of oxygen."
- AAP
