The Coalition rose four points to 45 per cent.
Labor also trails the Coalition 46 per cent to 54 per cent after preferences, after tying with the Coalition at 50 per cent a fortnight ago.
Ms Gillard’s personal popularity has also plunged.
Ms Gillard broke an election promise when she announced plans for a carbon tax which will start in July next year before morphing into an emissions trading scheme.
The details of the carbon tax and the amount of compensation are yet to be determined, and the Government has been under pressure from the Opposition to explain how the tax will affect households and the wider economy.
Ms Gillard told reporters in Washington that she was not deterred by the poll’s results.
“It’s fairly easy to stoke fears, and Tony Abbott is a master of it, and he will continue to stoke fears,” she said.
“But Australians, I believe, will come to see that pricing carbon is the right way of dealing with climate change and the challenge of it transforming our economy.”