Some of the nation’s most powerful business peak bodies have been taken on by the consumer watchdog over their claims that the carbon tax would cause power prices to rise by up to 20 per cent over the next year.

Two solar companies were swooped on by the Australian Competition and Consumer Commission for ”misleading” carbon tax advertising that stated the carbon price would increase power electricity prices 20 per cent this year and up to 400 per cent higher by 2019.

The stoush came as the Prime Minister, Julia Gillard, confirmed the government was involved in discussions on the planned floor price for carbon permits.

It is understood there are no discussions to scrap the floor price but the government is in talks with the Greens on how to tackle the fraught issue of stabilising the price of permits once the carbon tax becomes an emissions trading scheme in 2015.

The ACCC deputy chairman, Michael Schaper, said that ACT Renewable Energy and Polaris Solar in Western Australia had made ”clearly misleading” claims in their advertising that urged people to buy solar panels to avoid the soaring electricity costs.

He also revealed that the 20 per cent claim had come from newspaper ads run by the Australian Trade and Industry Alliance, an anti-carbon tax group made up of the Minerals Council of Australia, the Australian Chamber of Commerce and Industry, the Australian Coal Association, the Australian Retailers Association, the Housing Industry Association and Manufacturing Australia.

”They said these [claims] were based on independent studies but when we went back and looked at them, they were basically third party stories … or advertisements made in newspapers and weren’t actually based on anything that would be regarded as a credible or reasonable source,” Mr Schaper said.

”That’s why we regard these as misleading.”

The ATIA ads did not, however, make the 400 per cent claim, which was made by the solar firms alone.

A spokesman for the Minerals Council challenged the suggestion that the 20 per cent figure was unsourced, saying the ATIA had drawn on figures from the NSW Treasury and the Energy Users Association of Australia.

The federal Treasury estimates that power prices will rise an average 10 per cent.

According to Mr Schaper, The two solar companies have agreed to stop using the ads. Their directors would attend training on consumer law.

Todd Obara of ACT Renewable Energy said there was ”more than one interpretation of the advertisement” and that the ”people of Western Australia and ACT are intelligent enough to make up their own minds in this regard”.