Opposition Leader Tony Abbott suffered a sharp drop in his approval rating as the Government surged to narrowly lead the Coalition in the latest Newspoll.

The figures published in this morning's Australian newspaper show Prime Minister Julia Gillard leading Mr Abbott 50 per cent to 31 per cent as preferred prime minister.

Labor leads the Coalition 51 per cent to 49 per cent in the two-party preferred race.

Two weeks ago the Coalition led Labor comfortably by 54 per cent to 46 per cent in the two-party standings.

Labor's primary vote is up from a record low of 30 per cent two weeks ago to 36 per cent, while the Coalition's primary vote has slumped from 45 per cent to 40 per cent.

The Greens' primary vote has also suffered a sharp drop, down from 15 per cent to 12 per cent.

But neither leader enjoys a net approval rating, according to Newspoll.

Forty-seven per cent of those polled are dissatisfied with Ms Gillard's performance, compared to 40 per cent who are satisfied; Mr Abbott fares even worse, with a 54-33 dissatisfied/satisfied score.

The telephone polling was conducted last weekend against a background of the carbon tax debate and the Prime Minister's visit to the United States, where she addressed Congress.

The Government painted Mr Abbott as a climate change denier after he apparently contradicted himself on climate science last week.

And the Government's chief climate advisor, Ross Garnaut suggested sweeping tax cuts to offset higher prices for power and fuel.

Newspoll CEO Martin O'Shannessy says Ms Gillard's approval was helped by her speech to Congress and more detail on how people will be compensated for the carbon tax.

"She's selling the upside [of the carbon tax] and particularly how there will be more dollars in the hands of families," he told AM.

He said Ms Gillard appeared to have won back traditional Labor voters from the Greens by rejecting gay marriage and euthanasia.

"There's a very clear path going through what happened in the last poll, the changes that Labor made in the last fortnight and what's happened in this poll which has brought them back to basically where they were at the end of last year."

Opposition Leader Tony Abbott used questions about the poll to ramp up his attack on the Government's carbon tax.

"I look at the field evidence, not the polls. And the field evidence is that this Prime Minister said before the election 'there will be no carbon tax under a government I lead'," Mr Abbott said.

"They didn't tell you the truth before the election and now they are going to use your money to advertise their broken promise."

Asked on commercial radio if he would survive the carbon tax and the poor polling, Mr Abbott said, "I expect so."

"You do not win elections by engaging in weak compromises with a bad government. You win elections by coming up with strong, consistent, clear alternative policies."

But Opposition Immigration spokesman Scott Morrison sheeted the result home to Foreign Minister Kevin Rudd's handling of the Libyan crisis.

"In times of international and major international events governments do tend to get a bounce, so it may well be that what we've seen in this poll has a lot more to do with Kevin Rudd than Julia Gillard," Mr Morrison said.

"Clearly Kevin Rudd, in dealing with the issue of the no-fly zone last week, I think he had broad support and he certainly had support from the Coalition on that matter.

"Julia may have Kevin to thank for today's poll numbers."