Peter Costello says he urged John Howard on several occasions to stand down as prime minister, but rejects the suggestion he lacked the guts to challenge for the Liberal leadership.

The former treasurer said he pressed Howard on the issue on a number of occasions, but that the former prime minister always had a reason not to hand over the leadership reins.

“On at least five or six times there was an occasion where he raised the prospect of handing over the leadership and a transition, and on each occasion there was a reason why he didn’t do it,” Costello said in an interview aired on the Nine Network tonight.

The interview comes ahead of the release of Costello’s memoirs on Tuesday.

“I told him … it should be done, and he didn’t agree with me, he didn’t accept it,” Costello said.

“I thought it should be done, I was very direct and very up-front with him.”

Costello denies he lacked the courage to challenge Howard.

“I put my case … very forthrightly, and I never had a majority.

“Now, it may say that I’m not as persuasive as I should have been. I’ll take that, but I put my case.”

He was also asked if he accepted whether his failure to challenge Howard showed he was gutless, spineless and indecisive.

“Of course not,” he said of each accusation.

And he again said he would not be seeking to depose Brendan Nelson as the Liberal leader.

“I will not seek, nor am I being drafted, and I am not seeking it.

“These are not weasel words. I said the day after the election I will not run, nor will I accept the leadership. That is my position.”

On Saturday, his father-in-law and memoirs co-author Peter Coleman said Costello had left himself “wriggle room” regarding the leadership.

However, senior Liberal Joe Hockey today said that there was no wriggle room because Nelson was doing a great job as leader.

“There’s no wriggle room, the leadership firstly is not vacant, Brendan Nelson is doing an exceptional job in difficult circumstances,” Hockey said.

Hockey said the public was bored with the on-going speculation over the Liberal Party leadership.

“Quite frankly, I think it is time for people to move away from focusing on the Liberal leadership and start focusing on the lack of leadership in the Labor Party.”

Costello will rejoin his colleagues in Canberra tomorrow when parliament resumes.

He has already attracted the ire of a few of his coalition partners after exerts of his long-awaited memoirs were published at the weekend.

In the book, the former treasurer has accused Nationals senator Barnaby Joyce of undermining the authority of that party’s former leader Mark Vaile.

But Joyce said it was Costello who had been undermining his own party leader.

“Undermine the leader? I’m not quite sure what Peter has been doing for the last six months,” Joyce said.

“I don’t know what you call writing a book about your colleagues whilst you’re actually sitting with your colleagues.”

Joyce said Costello should quit politics immediately.

“You’re either in or you’re out. He said he’s out, so you’ve got to go out.”