The Liberal-National coalition is on track to hold as many as 78 seats in the new parliament, giving it a working majority, as counting continues.
Prime Minister Scott Morrison looks likely to win at least 77 seats, possibly 78, allowing him to appoint a Speaker and govern in majority in the lower house.
The count in the NSW seat of Macquarie took a turn on Monday afternoon, with the Liberals' Sarah Richards edging ahead of Labor MP Susan Templeman.
There were just 50 votes separating the pair on Monday evening, according to the Australian Electoral Commission website, with more than 86 per cent of all ballots counted.
The Liberals also appeared on track to win the Labor-held seats of Chisholm in Victoria, and Bass in Tasmania.
In Bass, the Liberals' Bridget Archer sits on 50.3 per cent of the two-party vote, ahead of incumbent Labor MP Ross Hart.
Liberal candidate for Chisholm Gladys Liu holds 50.4 per cent of the vote, ahead of Labor's Jennifer Yang.
If the current count trends continue, this will give the Liberals 78 seats in the 151-seat House of Representatives, with Labor on 67 and six crossbenchers.
Independent MP Kerryn Phelps conceded defeat in the NSW seat of Wentworth on Monday, losing to the Liberals' Dave Sharma after only six months in parliament.
"I operated in Canberra with conviction, with integrity and a belief that individuals can impact on the political conversation," Dr Phelps told reporters on Monday.
The Australian Electoral Commission said counting of postal votes would be underway in all 151 seats on Tuesday, having initially prioritised postal votes in Boothby, Chisholm, Cowan, Macquarie and Wentworth.
The AEC said it had to wait 13 days after election day, by law, until the cut-off for any postal votes.
However, officials said some final results may begin to be formally declared by the end of this week.
In the previous parliament the numbers were: Liberals 58, Nationals 16, Labor 69, Greens 1, Centre Alliance 1, Katter's Australian Party 1, independents 4.