Three million Queenslanders are heading to the polls to decide who will lead the next state government.

After 28 days on the hustings, Premier Annastacia Palaszczuk and Liberal National Party leader Tim Nicholls will join the battlers, city slickers and undecided in the fight for their political lives.

But it could be days before a final result is delivered, with counting of booths and pre-polls to be get underway on Saturday while the hundreds of thousands of postal and absentee vote calculations begin on Sunday.

It took more than a week before Labor could claim power in 2015, after the LNP was resoundingly dumped after a single term.

This time, the resurgence of One Nation and return of compulsory preferential voting will further complicate Labor and the LNP’s chances of winning a majority government.

Ms Palaszczuk and Mr Nicholls are both in for a tough fight, with Labor claiming a narrow lead over the LNP in the latest polling.

The premier will start the day on the Gold Coast before returning to her southwest Brisbane electorate to cast her vote at Inala State School.

Mr Nicholls will help his 78-year-old father, Peter, at a polling booth in his blue-ribbon Clayfield seat.