The counting of postal votes continues today in the seat of Fairfax on Queensland's Sunshine Coast, where businessman Clive Palmer is holding on to a slender lead.

At one stage yesterday Mr Palmer fell 18 votes behind Liberal National Party (LNP) candidate Ted O'Brien but later recovered to lead by just three.

As of this afternoon, the Australian Electoral Commission (AEC) said Mr Palmer's lead had been extended to 98.

The deadline for postal votes is 6:00pm tomorrow.

Electoral official David McKenzie says the final pre-poll and postal votes will be counted on Saturday, but that may not be the end of the matter.

"There's always the opportunity for a candidate to formally request a recount because if it's outside the 100 we won't automatically initiate one but a candidate may like to request one," he said.

"They would need to cite specific reasons for why they believe a recount would change the result.

"Once we have declared, the candidates also have the right to challenge the result in the Court of Disputed Returns.

Mr McKenzie says there have been 30 to 40 scrutineers a day keeping a close watch on AEC staff.

"We had to remove all of the scrutineers from the building this morning and have a briefing with them to lay down some changed guidelines so that we could resolve those sorts of issues," he said.

"It's been very tense at times but the candidates' appointed representatives have been extremely professional."

Mr Palmer has already said he wants a recount regardless of the outcome.

The leader of the Palmer United Party has been outspoken about "irregularities" in the electoral system.