Australia's ruling Labor party is heading for a huge defeat in elections this year, according to the first national polls Monday since Prime Minister Julia Gillard announced a vote would be held in September.

Labor ministers insisted a win was still possible as major surveys suggested Gillard's gamble to announce the election early was backfiring, with one showing her party slumping behind the conservatives by a yawning 16-point margin.

A Newspoll for The Australian newspaper showed Labor's single party support plunged six points to 32 percent, while the opposition strengthened four percentage points to 48 percent, in the past three weeks.

On a two-party basis, taking into account alliances with minor parties, the coalition holds a 56 percent to 44 percent lead in the poll of 1,163 people.

A separate poll of 1,015 voters in Sydney's Daily Telegraph, conducted over the weekend, showed a similar headache for Labor with the coalition having a 54 to 46 lead on a two-party basis.

Since calling a near eight-month election campaign, Gillard, Australia's first female leader, has endured a turbulent time with two of her most senior ministers resigning and an ex-Labor MP arrested on fraud charges.

But Labor figures rallied behind her Monday in a television and radio blitz.

"I am very confident we can turn it around," Transport Minister Anthony Albanese told ABC radio, adding that as the election draws closer there will be more examination of opposition leader Tony Abbott's "failures".

Senior frontbencher Simon Crean urged the party to "hold its nerve".

"We can win it, it is doable, it is difficult, but we've got to hold our nerve and our conviction and our belief in not just what we've done, but what we plan to do," he said.

Deputy opposition leader Julie Bishop said the poll came as no surprise.

"There have been many comments by Labor members and senators over the last week expressing a lack of confidence and trust in her (Gillard)," she said.

"It shouldn't be a surprise to anyone that the community is feeling the same."

Gillard announced the election date early, breaking from the tradition of revealing it only a few weeks in advance, in part to force the opposition to detail its policies and costings.

Addressing Labor candidates on Sunday, she said she was committed to creating jobs and improving opportunities and it was important that voters heard this message.

"I'm looking to you to be out there in your communities explaining to them that this is the work of governing and we are not done yet," she said.

Following a cabinet reshuffle after attorney general Nicola Roxon and minister for tertiary education Chris Evans quit for family reasons on Saturday, several new ministers were sworn in Monday.

They included Mark Dreyfus as attorney general, Brendan O'Connor as immigration minister and Chris Bowen as tertiary education minister.