Minor party preferences will decide who wins the next Queensland election, with both major parties a long way short of commanding enough direct support to win, according to an opinion poll on the eve of the expected campaign.

The Newspoll in The Australian has the Palaszczuk Labor Government leading the Nicholls LNP Opposition 37 per cent to 34 on the primary vote, with One Nation polling 15 per cent and the Greens 8 per cent.

Although the ALP will not seek One Nation preferences, second preferences will be crucial to the outcome, with full preferential voting now compulsory after years of "just vote one" being an option for voters.

Newspoll predicts most Green preferences will go to Labor along with almost half of One Nation preferences, to give Labor a two-party preferred lead of 53 to 47.

But that prediction becomes less certain if the LNP ends up getting a much higher proportion of the One Nation vote.

Mr Nicholls' LNP would get 34 per cent of the primary vote, according to the latest poll. ( AAP: Dan Peled )

Premier Annastacia Palaszczuk would not say if the poll result tempted her to begin the formal campaign period soon.

But she did not rule out the widespread expectation that the election would be held in October or November.

"It's my intention to go next year, there's still a lot of work to do," Ms Palaszczuk said.

"I'll take you into my confidence: when I call the election, I will let you know."

Almost half of One Nation's preferences are predicted to be delivered to Labor. ( ABC News: Jed Cooper )

Labor's primary vote of 37 per cent is the same as its 2015 election result but the LNP's 34 per cent is a seven point drop since 2015.

Ms Palaszczuk and Mr Nicholls have each suffered slides in their personal ratings, with more voters dissatisfied with both leaders than satisfied.

The Premier said she was not disappointed about that.

"No, not all," she said.

"I'm out in the public all the time. I am very humbled by the support that Queenslanders are placing in me."