Former Queensland Speaker John Mickel has warned Labor could suffer another “Mundingburra” where a single seat costs it government due to an electoral anomaly.

Ferny Grove is the seat under the spotlight, almost 20 years after the Goss government lost power following a by-election in the Townsville electorate of Mundingburra.

The northwest Brisbane seat is on a knife-edge, one of five electorates still in doubt after four days of counting that currently has Labor poised to win 44 seats and the LNP 42.

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Labor’s Mark Furner was about 370 ahead of the LNP incumbent Dale Shuttleworth in Ferny Grove on Tuesday afternoon.

But Electoral Commission Queensland (ECQ) received advice that Palmer United Party candidate Mark Taverner, who has picked up 800 votes, could be an undeclared bankrupt.

ECQ is seeking Crown Law advice about whether he’s eligible, whether there’s any precedents and whether Mr Taverner’s status would necessitate a by-election in the seat.

However, Mr Taverner’s small proportion of the overall vote, when absentee and postal votes are included, may not affect the outcome, so there may be no need for a by-election.

The only other way Ferny Grove voters could potentially to go back to the polls is if another candidate lodges a complaint with the Supreme Court.

Mr Mickel said there could be a by-election in the seat, which would resemble the Mundingburra by-election in 1996.

“A government will need to be formed,” he said.

“The makeup of that government and whether it survives may come down to a by-election.”

A seat Labor was more likely to pickup is Maryborough where Bruce Saunders was almost 1200 votes ahead of the LNP’s Anne Maddern on Tuesday afternoon.

In southwest Brisbane, LNP incumbent Tarnya Smith was 476 votes ahead of Labor’s Jessica Pugh in Mount Ommaney, while in the central Queensland seat of Whitsunday the LNP’s Jason Costigan was leading Labor’s Bronwyn Taha by 163 votes.

There’s also been a dramatic day of counting in Lockyer where One Nation founder Pauline Hanson has been hoping to make a political comeback in her ninth election.

Ms Hanson gave LNP incumbent Ian Rickuss a scare, but she’s currently trailing him by 122 votes and pundits say she’s unlikely to get over the line.