Last-minute win hampers NSW Labor's legislative agenda

The NSW Labor government will be forced to delicately negotiate with the crossbench to pass legislation after the Liberal Party scored the final seat in the upper house.

More than three weeks since polls closed, the NSW electoral Commission distributed preferences on Wednesday, leaving the the upper house chamber evenly split between the left and right wings.

The result leaves the government and coalition opposition with 15 members each, meaning Labor will either need the support of a right-wing crossbencher to pass bills or convince a right-wing MP to take the president's chair.

Liberal Party candidate Rachel Merton, a former Australian Classification Board member and Perrottet government staffer, narrowly won the 21st and final seat from the Animal Justice Party's Alison Waters.

The four Greens members, Animal Justice's Emma Hurst and newly elected Jeremy Buckingham of Legalise Cannabis represent left-wing parties.

Election analyst Kevin Bonham said Labor had a history of working well with the right-wing Shooters, Fishers and Farmers Party.

The party will have two seats in the new chamber after party leader Robert Borsak was re-elected.

Labor could also negotiate with former Liberal party member John Ruddick, elected for the Liberal Democrats.

But the government has ruled out dealing with One Nation leader Mark Latham after his homophobic comments towards a sitting MP last month.

One Nation secured one spot in the chamber but failed to replicate its 2019 result when it scored two.

One Nation's second candidate, former Labor MP Tania Mihailuk, is expected to inherit the seat Mr Latham vacated before the elections.

Wednesday's result was third time unlucky for the Animal Justice Party which won one seat in each of the past two elections on the final count of preferences.

A second count of ballots in recent days helped the party's candidate close the gap to Ms Merton to 0.069 of a quota.

Ms Merton spent 14 years in government relations at KPMG before a two-year stint on the board of Australia's classifier for film, computer games and publications.

Her most recent role was as deputy chief of staff to Natasha Maclaren-Jones, the families minister in the Perrottet government.

"As a full-time working mother for the past decade Rachel has a strong understanding of the challenges women face in juggling the competing demands of raising children while in the workforce," the Liberal Party said before the election.

The parliament returns on May 9.