Tony Abbott is in the fight of his political life against barrister and former Olympic skier Zali Steggall who's trying to wrestle the northern beaches seat away from him.
Both candidates have been on the receiving end of dirty tricks during the campaign.
Abbott called out "nastiness" in politics after offensive posters were plastered around the former prime minister's electorate and poo was hidden inside a book dumped outside his Manly office.
The campaign hasn't been kind to Steggall either. Conservative activist group Advance Australia filmed its mascot - Captain GetUp - rubbing against one of her billboards in a sexualised way while her ex-husband called her an "idiot" on Twitter.
Steggall, an independent, has been riding a wave of discontent with the local Liberal member in an electorate increasingly concerned with climate change.
Abbott, who suffered a nine per cent primary vote swing against him in 2016, campaigned on a host of local issues including upgrades to walking tracks and surf lifesaving toilets in an electorate he's represented for 25 years.
Steggall is selling herself as a "sensible centre" candidate in Warringah which has only ever been held by the Liberal party.
Liberal candidate Dave Sharma is trying to reverse the defeat he suffered in October's by-election when independent Dr Kerryn Phelps won the seat vacated by Malcolm Turnbull after he was deposed as prime minister.
The Liberals, who had never lost the seat, suffered a 19 per cent swing in the by-election and now sit 1.2 per cent behind Phelps on a two-party-preferred basis.
But the party is hoping time heals all ills and the anti-Liberal sentiment has subsided in the blue-ribbon seat.
Phelps has been subject to some vicious campaign tricks with homophobic emails circulated stating she's ineligible to run for parliament and asking voters to "shred" her campaign posters.
Sharma, the former ambassador to Israel, condemned the "bigoted" emails.
Labor's Tim Murray is running again after receiving 11.5 per cent of the primary vote in the by-election.
Climate change and social policy are again likely to sway voters.
The marginal seat of Lindsay in Sydney's west is one of the few Labor-held seats the Liberals believe they have a strong chance of reclaiming after Emma Husar announced she'd quit following allegations she mistreated staff.
The ALP holds Lindsay by a margin of just one per cent after Husar took the seat off Liberal Fiona Scott in 2016.
A series of scandals and workplace bullying accusations in 2018 forced Husar to announce she wouldn't recontest the seat before she later changed her mind. But in mid-April, she confirmed she wouldn't run again as an independent.
Labor pre-selected former state politician Diane Beamer as its candidate. Some NSW Liberals believe the party has a chance to pinch Lindsay following favourable state election results in Sydney's west.
The Liberals held the state seat of Parramatta, which falls within Lindsay, in the March state election despite predictions it would fall to Labor.
Beamer is up against Liberal Melissa McIntosh who worked for Wentworth Community Housing and is campaigning to improve local road and congestion issues.