The battle for the final electorate in play after the NSW election - the tightest contest in years - will continue as Labor seeks a recount in one crucial seat.
Electoral analysts called the northern Sydney seat of Ryde for the Liberal Party after postal votes showed former mayor Jordan Lane 50 votes ahead of his Labor opponent, former councillor Lyndal Howison.
Ms Howison has asked the electoral commissioner to conduct a recount.
The commissioner can act upon recount requests from candidates or off his own bat.
The recount could delay the declaration of results in all 93 lower house seats, which was expected to take place on Friday.
Mr Lane aims to replace outgoing Liberal minister Victor Dominello, who previously held Ryde by almost nine per cent.
After the check of the district's 55,278 votes was completed on Saturday, the 28-year-old held a 50-vote lead over Ms Howison 25,425 to 25,375.
But the Labor candidate and high school teacher's path to victory could lie in the 1447 ballot papers considered informal and another 3031 considered exhausted for not having a clear Labor or Liberal preference.
Any declared result could still be challenged through the filing of a petition with the Court of Disputed Returns.
If Labor does miss out on Ryde, it will need two cross bench MPs to pass legislation through the lower house.
Three, including likely speaker Greg Piper, have already guaranteed confidence and supply.
Mr Lane would be the coalition's 36th seat, nine fewer than before the election.