Photo: © 2010 AAP/LISA MARTIN

The Australian newspaper's latest poll has the Opposition nudging ahead of the Government, with 51 per cent of the two-party preferred vote.

And while Rudd is still the preferred Prime Minister, by a margin of 50 – 32, his personal approval rate has taken the sharpest dip in Newspoll history.

It has plunged from 50 per cent to 39 per cent in a fortnight.

"These numbers are probably telling us there is a protest vote ... probably against the shelving of the ETS," Newspoll's Martin O'Shannessy said in today's edition of the paper.

Labor has been clearing the decks of bad news and broken election promises in recent weeks to give itself a smooth run at re-election later in the year, and Rudd is standing by his recent policy backflips.

"My job as prime minister is to act in the Australian national interest whether decisions I take are popular or not," he said today.

"I don't intend to change that in the future, for the simple reason that acting in the national interest is fundamental for our country's future."

Opposition Senator Barnaby Joyce says the poll reflects the incompetence of the incumbents on issues like the climate change.

"Everything that they touch has turned into not a stuff-up, [but] a complete and utter cluster-stuff," he told ABC Radio.

But Opposition leader Tony Abbott says his side faces a "political Everest" to win office.