FORMER federal Liberal leader John Hewson says it's time for his party to set aside its political interests and support a carbon price in the national interest.

Dr Hewson has joined former prime minister Malcolm Fraser, actor Cate Blanchett and more than 140 community leaders in the "We Say Yes" campaign - a $1 million advertising and grass-roots campaign backing government plans for an emissions trading scheme.

The multi-party climate change committee, created after the 2010 election to come up with the details of the scheme, includes Labor, the Greens and independents.

But Dr Hewson said he was "disappointed" the Liberal party has not been involved, as it had options to put on the table and the process could have been depoliticised.

"The way I see their direct action package it puts an implicit price on carbon," Dr Hewson told reporters in Canberra today.

"So it's not a debate on putting a price on carbon - it's how best to put a price on carbon."

Opposition Leader Tony Abbott was "master of the negative" and was leading in the polls, but in time "we will have a price put on carbon and ... opinion will just sort of blend together".

Dr Hewson said he had no problem speaking out as he was "an Australian first and a member of the Liberal party second".

Asked about the cost of living impact, he said that a properly set-up emissions trading scheme under an independent authority could reap more than enough money to adequately compensate low and middle income earners for any price rises.

Nationals leader Warren Truss took a swipe at the celebrities and "political has-beens" featured in the campaign.

"Australians don't like being preached at," he said.

"The cult of celebrity plays very well in the US, but Australians are more discerning and their bulldust barometers are well tuned."

Prime Minister Julia Gillard defended the role of Blanchett.

"Cate Blanchett has had her voice heard on climate change, that's appropriate, just as it's appropriate for one million women to have their voices heard," Ms Gillard told reporters after launching the "1millionwomen" climate change campaign in Sydney.

Climate Change Minister Greg Combet said the government would fund its own information campaign when the ETS details were completed.

"It's important we engage with the community to explain that," he said.

Meanwhile independent MP Tony Windsor, who joined other members of the multi-party climate change committee for a meeting in Canberra over the weekend, said his final view on carbon pricing would be heavily influenced by a Productivity Commission report on global climate efforts due to be presented to the government tomorrow.

"If that's proven to be the case (that other countries are acting), then I think the answer is a carbon price," Mr Windsor told ABC radio.