Former Opposition Leader Malcolm Turnbull has accused the man who replaced him as leader, Tony Abbott, of changing his position twice on climate change.

Mr Turnbull says Mr Abbott moved from supporting a carbon tax, to supporting a market-based emissions trading scheme and then opposing both policies outright.

And he says having done that, Mr Abbott resigned from shadow cabinet in 2009 to challenge him for the leadership.

But he says he has given Mr Abbott "consistency and loyalty" that he, himself, did not enjoy as leader.

"He [Mr Abbott] had been in support of a carbon tax at one point, he supported an emissions trading scheme," Mr Turnbull told ABC radio in New England.

"Then - and I'm not suggesting that he did so other than what were for good reasons - he changed his position and resigned from the shadow cabinet and challenged me for the leadership and was successful.

"I have given Tony Abbott a consistency and loyalty that I didn't receive consistently from my colleagues when I was leader.

"But I've given him that consistency and loyalty and that's why I'm saying our position is to oppose the Gillard Government's carbon tax and I'm not deviating from the Coalition's position."

He said the Coalition supported an emissions trading scheme under John Howard and went to the 2007 election "with that as our policy".

"After Tony Abbott took over from me as leader of the Liberal Party the policy was changed to one of absolute opposition to any emissions trading scheme."

Mr Turnbull has said he still personally supports a market-based emissions trading scheme and has described the Opposition's "direct action" plan as expensive and easy to dump.

But today, asked if the Government's carbon price plan has merit, he was more circumspect.

"Look, I think the best thing I can say is not express a personal view and just simply say that the Coalition's policy is to be opposed to it," he said.

"We are part of a collective, I'm part of a shadow cabinet so whatever personal views we might have - and people come to these things with a range of personal views - we form a collective position and that is the position of the Coalition.

"The position of the Coalition is to be opposed, to vote against in other words, the carbon pricing mechanism of the Gillard government."