The recount in the final outstanding federal seat of Herbert could be completed as early as Tuesday.
The most recent figures published by the Australian Electoral Commission on Monday afternoon put the sitting coalition MP Ewen Jones 12 votes ahead of his Labor rival Cathy O'Toole.
Coalition senator Ian Macdonald, who has been keeping a close eye on the count, wrote on Twitter on Monday an electoral officer was examining "challenge votes".
Senator Macdonald said it was possible the result could be finalised on Tuesday.
"Too close too call," he wrote.
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If the coalition can retain Herbert, the Turnbull government will have 77 seats in the 150-seat parliament.
Shadow attorney-general Mark Dreyfus has written to the prime minister to query the involvement of Attorney-General George Brandis in the recount.
It's likely Labor or the Liberal National Party will take the final result to the Court of Disputed Returns and argue for a fresh poll.
A number of anomalies have been reported, including the possibility that soldiers based in Townsville were among 628 ADF personnel who were on Exercise Hamel in South Australia during the election campaign and did not cast their votes.
