AAPUpdated July 14, 2013, 11:43 am

Labor will stick to its plan to return to surplus despite moving to a floating carbon price a year earlier than planned, Treasurer Chris Bowen says.

Mr Bowen said the plan would ease cost of living pressures for families and support the non-mining sector

The Australian Greens say the move means Prime Minister Kevin Rudd is a fake on climate change while Opposition Leader Tony Abbott called it more fake change from the prime minister.

The move would see the current fixed $24.15 per tonne carbon tax dumped in favour of a floating price which could be between $6 and $10 per tonne.

Australia had previously planned to move from a carbon tax to an emissions trading scheme by July 2015.

Mr Bowen says Labor was moving to the floating price earlier to support the non-mining sector of the economy and families concerned about cost of living pressures.

“There is a substantial impact on the budget of doing this, of course there is, and it is several billion dollars, but we will be financing that in a fiscally responsible way,” the Treasurer told Ten’s Meet the Press on Sunday.

But he insists the budget will remain on track for a surplus with yet to be announced spending cuts to accompany the change because the government will be losing planned revenue.

“It means ensuring that our strategy of returning to surplus over the economic cycle – balance in 2015/16 – is adhered to, so it is a challenge.”

The Treasurer said there would be no change to the household assistance plan, and any decisions on spending cuts will be made with families’ cost of living concerns in mind.

“I think families will see a big benefit in what we are bringing forward,” he said.

He didn’t say how much families would save but said he’d seen figures speculating how much families might save on bills and they were “broadly right”.

Mr Abbott said the shift would represent “more fake change from Kevin Rudd”.

“If it’s bad at $23 a tonne, it’s bad at $10 a tonne, it’s a bad tax, you’ve just got to get rid of it,” Mr Abbott told reporters in Sydney on Sunday.

Senator Milne says Mr Rudd is a “fake” on climate.

“It is cowardly,” she told ABC’s Insiders program.

“If you believed that climate change was the greatest moral challenge or our time, and it is, we are living in a climate emergency, you would now not be moving to have the big polluters pay less.

“That is what Kevin Rudd is doing. It is all about politics and not policy.”

John Connor, chief executive of The Climate Institute, says emissions trading puts not just a price, but also a limit, on carbon pollution.

“Any decision to bring it forward a year should come with a statement of increased ambition, strengthened domestic policy and a continued integral role for the independent Climate Change Authority,” he said.