Labor leader Kevin Rudd's meetings with Brian Burke show the new opposition leader's inexperience, Prime Minister John Howard says.
Mr Rudd suffered his most bruising day since becoming leader as he tried to distance himself from the political corruption scandal engulfing Labor politics in Western Australia.
Mr Rudd said he made a mistake by agreeing to meet Mr Burke, the disgraced former WA premier, three times in 2005.
At the time, state ministers had been banned from having any contact with Mr Burke, a convicted fraudster and political lobbyist.
Mr Rudd said he was not aware of the ban when he met Mr Burke for breakfast, over coffee and at dinner with federal Labor backbencher Graham Edwards, a close personal friend of both men.
He also could not remember who paid for dinner at Perth restaurant Perugino on August 1, 2005.
Mr Howard said Mr Rudd was being disingenuous, particularly after his attacks on Foreign Minister Alexander Downer and then trade minister Mark Vaile over the AWB scandal.
"It does demonstrate a very serious error of judgment, a lack of experience on Mr Rudd's part," Mr Howard told Regional Radioworks.
"He can hardly say he didn't know the gun was loaded, so to speak.
"It's disingenuous to say 'I didn't know about this, I didn't know about that'. Here's the bloke who was demanding that Alexander Downer and Mark Vaile recall every detail of thousands of cables that have been sent to their office in relation to AWB.
"I think it is disingenuous."
Three WA state ministers lost their jobs recently after their dealings with Mr Burke were revealed by a Crime and Corruption Commission (CCC) inquiry.
The government accused Mr Rudd of enlisting Mr Burke as his numbers man for a leadership challenge against Kim Beazley a year after the meetings.
Mr Edwards denied that allegation, saying Mr Rudd never touted for political favour from Mr Burke.
Mr Edwards told Radio National he had been keen to introduce Mr Rudd to Mr Burke because the now Labor leader was a "bright, young bloke" and it was important he get to know the state of WA and its people.
Mr Howard said Mr Edwards had backed the government's argument.
"Graham Edwards confirmed what we had suggested and that is that this was about building popularity and support in Western Australia," Mr Howard said.
"That is code in politics for promoting him as a future leader."