Media magnate Rupert Murdoch says Kevin Rudd is too sensitive to media criticism and is more interested in strutting the world stage than running Australia.
The News Corporation chairman says Mr Rudd has been more responsive to adverse media reports than previous Australian leaders.
"He doesn't like criticism," Mr Murdoch told Sky News.
"He expresses his complaints more vociferously and faster."
Mr Rudd has been upset with coverage in News Ltd newspapers of Labor's school-building stimulus program and what turned out to be a fake email from former Treasury official Godwin Grech about the federal OzCar scheme.
"He's oversensitive and too sensitive for his own good," Mr Murdoch told The Australian newspaper this weekend.
But he said politicians all over the world suffered from a similar affliction.
"In their own interest they would be better employed reading something else, or be more laidback about it."
Mr Murdoch believes the prime minister is "very able, intelligent and interesting", but far too interested in making his mark on the global stage.
"He's different in that he's more ambitious to lead the world than to lead Australia," he told Sky News, but quickly added that the comment may be a "little unfair" though "there's some truth in it".
Mr Murdoch said it was ridiculous for Australia to think it could lead the world in tackling climate change.
"I don't believe that Australia trying to be first in the world with cap and trade ... is going to have any influence on the rest of the world," he said.
"We don't matter that much - let's be honest with ourselves."
Questioned about the media mogul's comments, Mr Rudd said he had not seen the remarks but added:
"Politics as we know here is a rough and tumble business. So there's always going to be criticism of what you do.
"I don't particularly mind. That's just life, you get on with it. We live in a free country. People can get out there and say whatever they like. And that's as it should be."
He said the government had a responsibility to act on climate change.
"That's my responsibility as prime minister. I intend to get on with it," he told reporters in Sydney.
"If people don't like it, well, that's fine. I don't care, it's a free country. But I'll get on with it.
"I also note, by the way, that when it comes to a robust debate, that there have been many, many things said in public about the importance of ensuring that we have a strongly robust and independent and free media.
"That's exactly what I support. It should be that way. If they criticise or support, it's a matter for them."
Opposition Leader Malcolm Turnbull agreed with Mr Murdoch, saying global climate change negotiations depended overwhelmingly on China and the US reaching agreement.
It was "delusional" and "absurd" to think that an Australian emissions trading scheme or an Australian policy was going to have this enormous impact on the deliberations of China and the US, Mr Turnbull told reporters in Geelong.
"I think Australia can play a very important part, but the idea that Australia or an Australian prime minister is going to be able to shift global opinion the way Mr Rudd seems to think ... If he genuinely believes that, he is deluded."
Mr Murdoch also told Sky News he doubted Australia needed so much stimulus spending.
"We were not about to collapse," he said.
"I thought we were trying to copy the rest of the world a little unnecessarily."
