The final ballots in the knife-edge Queensland seat of will not be counted until Saturday.
Businessman Clive Palmer has a 98 vote lead over Liberal National Party (LNP) candidate Ted O'Brien.
The deadline for postal votes is 6:00pm (AEST), with electoral officials saying they will still have to count the final ballot papers tomorrow morning.
Returning officer David McKenzie says it has been an intense two weeks of counting.
"There's been an incredible amount of interest from the parties and their candidates and also from the media," he said.
"Just managing all those expectations and dealing with the processes involved, it's been a very challenging environment, but very enjoyable as well."
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.