Finance minister Penny Wong has conceded that the downward spiral in the popularity of Prime Minister Julia Gillard is not unexpected.

A Newspoll survey revealed in The Australian newspaper shows previous prime minister Kevin Rudd shooting up to 21 percentage points to 57 per cent as preferred ALP leader, while Ms Gillard's rating fell five per cent to 24 per cent.

"Obviously this isn't entirely unexpected given what we've seen over the last week," Senator Wong admitted to ABC Radio.

"But what I would say is this: leadership is leading the party and the nation when times are tough as well as when things are easy.

"And what we have in prime minister Gillard is a person who is both decent and tough."

The government's primary vote remained steady on 27 per cent while the coalition has a commanding lead with 50 per cent and the Greens are polling 12 per cent.

In the two-party preferred vote, the coalition gained two percentage points to 59 per cent, while Labor fell two points to 41 per cent.

Ms Wong confirmed and vowed her support for Ms Gillard's leadership. Ms Gillard's leadership has come under fire since the High Court rejected the government's proposed asylum seekers swap deal with Malaysia.

"We have a prime minister, Prime Minister Gillard, and she's doing the right thing by the nation and she'll be leading us until the next election.

"These are difficult times. We have a very large set of reforms. Many of them are highly contested but Julia Gillard, Prime Minister Gillard, is pressing ahead with those and that's the right thing to do."