Labor's climate change spokesman, Mark Butler, and leader, Bill Shorten, have denied reports they are planning to propose a carbon tax. Credit:Alex Ellinghausen It is not clear who outside Labor has accessed the discussion paper. The party's environment spokesman Mark Butler said on Wednesday it was in "discussions with stakeholders" on the proposal, however it is understood the document itself was not widely circulated outside Labor. News Corp reported on Wednesday that Labor has drafted new plans for a carbon tax, ahead of the ALP's National Conference at the end of the month. The document is reported to include a "modified" version of the original carbon tax and a new tax on the electricity tax. It is also reported to include emission standards for cars, which would boost the cost of a new car by $1500, new laws to govern power plants, ­energy efficiency targets to include the family home and an "Electricity Transformation Plan" to phase out coal for renewable energy.

In Townsville, Mr Shorten firmly rejected suggestions the party planned to introduce a carbon tax. He said there had been repeated calls for Labor to reveal details of its climate change policy, and questioned why people were "hot and bothered" when a discussion paper emerged. "Australians are sick and tired of baseless scare campaigns," he said. "It is not in our discussion paper, or in our view at all, to have a carbon tax. But … we won't stick our heads in the sand, bury ourselves in the past and ignore climate change." The party would focus on renewable energy – in contrast to the government "who doesn't like solar power, doesn't like wind power, is walking away from investing in it," Mr Shorten said, in reference to a draft directive to the Clean Energy Finance Corporation to shift funding away from such technologies.

Mr Butler described the News Corp reports as "misleading". "In the late part of the last Labor government ... we took a decision to terminate the carbon tax and that remains very much Labor's policy," he said. "We have been clear though, that we will take to the 2016 election an emissions trading scheme that will place a legal cap on carbon pollution that then lets business work out the cheapest and the most effective way to operate. "This is the sort of scheme you see operating in North America, in the United Kingdom, in places like Germany and France and increasingly in our own region like South Korea and China." Avoiding a repeat of history

Labor has been at pains not to revisit the controversial "carbon tax" that dominated the Coalition's attack against the Gillard government. An ETS is understood to mean there is a cap on emissions, and requires emitters to have permits, which they can then buy or trade with other emitters if they want to emit more than their cap. A carbon tax involves a price on carbon emitted. Mr Butler said the leaked document was merely a briefing paper to inform discussion, not a policy document. "I want to stress this is just one of a series of papers that have been prepared and there has not even been the beginning of a discussion yet in shadow cabinet about this," he said. Mr Abbott seized on the News Corp reports on Wednesday.

"We have always said … that if Labor came back the [asylum seeker] boats would be back, the mining tax would be back and now we find out ... the carbon tax would be back," he said. "This just shows that Labor can't learn and hasn't changed. "[Labor] wants to damage our economy by reintroducing … a triple whammy carbon tax on households, on power stations and on cars." Environment Minister Greg Hunt said the plan would lead to a "massive hike" in electricity, gas and fuel prices. "But there is also a split [in Labor] of catastrophic proportions," he said.

"Who leaked Labor's plan? Why did they leak Labor's plan? Was it a plan to kill the tax or kill Bill?" Mr Butler said while the leak was "unfortunate" the party remained focused on taking a serious climate change policy to the next election. "Obviously I'm concerned that [someone] through carelessness or someone wanting to big-note themselves has provided an options paper … to the News Limited paper," he said. "Of course I'd prefer that wasn't the case". 'Not the biggest thing'

Labor MP Richard Marles said the leak paled in comparison to that following a heated cabinet discussion on national security last month. "This sort of thing happens in politics, it's not the biggest thing in the world," he told Sky News. Mr Marles said economies around the world were using emission trading schemes that harnessed the free market to tackle climate change - a threat the government "have their head in the sand about". "In Tony Abbott you've got a man that basically sees that climate change is crap. He is anti science and he is trying to take our country back to the stone age," Mr Marles said. He described claims that Labor wanted to damage the economy as "hyped-up rhetoric".

Treasurer Joe Hockey described the proposal as "madness". "I mean the situation here is Bill Shorten now wants not one carbon tax but two carbon taxes and you have to ask yourself, why would he want to do this? "I mean we are meeting and in fact beating our emissions reductions targets without hurting the Australian economy and given that the carbon tax brought down two Labor leaders, Kevin Rudd and Julia Gillard, it would be madness for Bill Shorten to follow that path. But obviously someone wants to kill Bill at the moment," he told ABC 24. The carbon pricing regime introduced by the Gillard government in 2012 was abolished by the Abbott government last year. Follow us on Twitter