Prime Minister Julia Gillard says she will "certainly" be leading Labor through to the next election and has described leadership speculation as "wasted breath".

The latest round of talk about a comeback by her predecessor Kevin Rudd was triggered last week by a flurry of polling showing disastrous results for the party.

However, Mr Rudd has indicated he will not mount a challenge and Ms Gillard has made clear she will not quit.

She says she is "completely" confident of leading the party through to the September 14 poll.

"I am the best person to lead the Labor Party," she said this morning.

Key points Defiant Julia Gillard says she will "certainly" lead Labor to election

Defiant Julia Gillard says she will "certainly" lead Labor to election Says leadership speculation a "waste of breath"

Says leadership speculation a "waste of breath" Gillard says she still has the backing of powerbroker Bill Shorten

Gillard says she still has the backing of powerbroker Bill Shorten Tony Abbott defends MP over "throat-slitting" comment

"I understand that these are difficult times, but people elect governments to do the big things our nation needs for the future, and they re-elect governments if they are achieving and getting those big things done. And that's what my focus is on."

She says there are no circumstances under which she will not be in the top job at the time of the election.

"No there are not," she said, adding "to make sure we haven't confused anybody with too many double negatives there - I will certainly be leading Labor at the next election.

"There's speculation, some of it is media speculating about media and journalists reporting the words of journalists.

"Yes there's rumour-mongering and speculation - it's wasted breath."

Gillard says she has Bill Shorten's backing

There is mounting pressure on Labor frontbencher and right faction powerbroker Bill Shorten to ask Ms Gillard to quit for the good of the party.

But Ms Gillard says she still has his backing.

"Mr Shorten has indicated publicly that he is supporting me as I get about this important work for the nation," Ms Gillard said.

Mr Shorten is allied with the Australian Workers Union, whose powerful national secretary, Paul Howes, is standing by the Prime Minister.

"What is happening at the moment, and you can't deny, is that there is a lot of whispering going on behind closed doors, and a lot of reporting going on by the nation's media, and that is truly distracting," Mr Howes told Channel Seven this morning.

"The more leadership speculation there is, the worse it is for the party."

Other key factional players have today publicly backed Ms Gillard.

Communications Minister Stephen Conroy, who is a leader of Labor's Victorian right faction, says she will lead Labor to the election.

He has moved to hose down renewed speculation, triggered by the ABC's Barrie Cassidy who said on Sunday that he was not relying "on his own guesswork" in coming to the view that Ms Gillard would not lead Labor to the election.

"I did have my weekend interrupted by Barrie Cassidy who decided to, as we say in AFL terms, bounce the ball and the ball seems to have dropped, hit the ground and everyone's staring at it going, what happens now?" Senator Conroy said.

"There's always a lot of colour and movement around this topic , but no - Julia will lead us to the election."

He added that Ms Gillard remains "strongly supported, overwhelmingly supported" within the Labor Caucus, and "nothing has changed".

South Australian Senator Don Farrell, who is also in the right faction and was instrumental in ousting Mr Rudd three years ago, says he continues to support Ms Gillard.

"Julia continues to, I believe, have the support of the overwhelming majority of the Caucus and she's going to lead us to the election," he told ABC radio in Adelaide.

Ms Gillard was speaking at a Brisbane school, where she called her first press conference in a week to increase pressure on Queensland to sign up to the Gonski school improvement plan.

Abbott defends MP over 'slit Gillard's throat' remark

Opposition Leader Tony Abbott, also in south-east Queensland today, has defended one of his backbenchers who last week said that Labor MPs want to "slit Julia Gillard's throat".

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Flanked by the Coalition MP in question, the member for the Gold Coast based seat of Moncrieff, Steve Ciobo, Mr Abbott played down the use of the term.

"I'm not sure that that's exactly what he said," Mr Abbott told reporters.

"But people often deal in metaphors.

"I think everyone knows what's meant, and I think there are a lot of Labor members of parliament right now stabbing the Prime Minister in the back metaphorically.

"No-one means it literally but we all know what's happening."

On Lateline on Friday night Mr Ciobo appeared in a television debate with Labor MP Nick Champion, who called his choice of words "an appalling way to refer to any politician".

Earlier this year, Mr Ciobo likened the Prime Minister to an alcoholic - another remark Tony Abbott was forced to defend.