But will Scott Morrison's "quiet Australians" be enough to bring him home to victory?

"I think there are millions of Australians out there - you know, between elections they are not reading the papers, or following the political news every day," he told a forum in Port Macquarie on Thursday.

"They are too busy living their lives and fulfilling their responsibilities to others.

"They are caring for parents or they're caring for kids, or they're just being the decent, honest, good-hearted Australians that they are.

"But they turn up every three years at elections and they take a good, close look at what the options are."

The undecided vote is a live issue for the coalition as the prime minister bids to save as many seats as possible.

But working against that is the record number of early voters - more than 1.5 million have already poured into pre-poll booths.

"There's a week to go in this election and lots of people have tuned out," Labor leader Bill Shorten told a cancer patient in Brisbane.

The polls sit in Labor's favour - somewhere between 51 and 52 per cent of voters are backing the opposition in two-party terms.

Both sides accept Morrison has been campaigning strongly in the hope undecided voters will swing in behind him.

But if Shorten is right that voters have already tuned out, then the PM's efforts might come to nothing.

The coalition will officially launch its election campaign in Melbourne on Sunday in what will be a low-key affair.

Labor's launch included the entire front bench on stage with Shorten, while a series of high profile women made speeches, and Julia Gillard and Kevin Rudd sat next to each other.

Morrison will likely not have his whole front bench there, he's light on women in senior roles, and Malcolm Turnbull and Tony Abbott won't be there.

And he will be in Victoria, where the coalition is worried it could lose a swag of seats it would usually expect to hold comfortably.

Last year's Victorian election was a nightmare for state Liberals, and the example worries the federal party.

One Victorian state minister this week said they went into the November state campaign expecting it to be really tight, and maybe end up in a minority government.

But once they got onto the pre-poll booths and saw the sheer number of early voters choosing Labor it was clear the government wasn't in trouble.

Coalition MPs handing out how-to-vote cards in their seats will have a fairly solid idea within the next few days about how they're travelling.

The coalition believes it has made up some ground on Labor.

"It could be one of those elections where we may not know the result on the night - which would be, from where we've come, remarkable," Liberal senator Arthur Sinodinos said at an event in Sydney on Wednesday night.

After the Sky News people's forum in Brisbane, one of the younger voters told AAP she was still undecided, but did like it when the leaders agreed.

"I think some people are turned off by negativity too, aren't they?" Shorten told reporters on Thursday.

Labor focus groups have shown younger voters especially don't like seeing their leaders bicker. They prefer them to agree on common sense solutions.

It's why Morrison and Shorten have both made a point of agreeing at various times with each other during the three debates so far.

But agreeing is not how voters' minds are changed.

The leaders have one week to win over those voters who enjoy the luxury of not having to care about politics until voting day.

"To those quiet Australians who are out there, now is not the time to turn back," Morrison said.

If Shorten is right, the Liberal leader might be speaking to deaf ears.

Australian Associated Press