Opposition Leader Tony Abbott has criticised Australian economists for supporting a carbon tax and a market-based emissions trading scheme as planned by the Federal Government.

But high-profile economist Saul Eslake has hit back, saying Mr Abbott's problem is that he cannot find an Australian economist who will support his "direct action" policy.

Speaking at a conference in Melbourne, Mr Abbott urged economists to "think again", saying they should go beyond the "allure of market-based mechanisms".

Mr Abbott cited Danish academic Bjorn Lomberg who, he said, had assembled a panel of international economists who do not think market-based mechanisms "are the way to go".

"They think that research is the best way to go, particularly government-funded research, adaptation and direct action is a better way to go than what we describe in this country as market-based mechanisms," Mr Abbott said.

"So it may well be that most Australian economists think that a carbon tax and an emissions trading scheme is the way to go.

"Maybe that's a comment on the quality of our economists rather than on the merits of the argument."

However, it is the credibility of Mr Lomberg rather than Australian economists which may not stand up to scrutiny.

In 2003 the Danish Committees on Scientific Dishonesty upheld a series of complaints laid about Lomberg's book The Skepical Environmentalist.

They included scientific dishonesty, selective discarding of unwanted results, deliberately misleading statistical evidence, plagiarism and deliberate misinterpretation of others results.

The findings were later declared invalid on procedural grounds.

Mr Eslake, program director with the Grattan Institute, told ABC News Online it appears Mr Abbott's criticism of Australian economists refers to an open letter signed by 13 of Australia's top economists backing a carbon price.

The letter, published last month, was signed by Chris Caton, chief economist at BT Financial Group; Besa Deda, chief economist at St George; Bill Evans, chief economist at Westpac and Mr Eslake among others.

It called for the speedy introduction of a price on carbon pollution, preferably by way of an emissions trading scheme.

"The frustration he has is that he can't find a single economist in Australia who supports his policy," Mr Eslake said.