A social media campaign targeting ethnic voters, with attacks on same-sex marriage, Safe Schools and asylum seekers has been blamed by Labor for its expected failure to regain heartland seats in western Sydney. 
Before booths closed on Saturday, the Liberals' most marginal NSW seat, Banks, was expected to be held by the Turnbull government, despite its history as a safe Labor seat before 2013.
Labor campaigners said a cluster of marginal multicultural seats - Reid, Banks and Barton - had been buffeted by "dirty" attacks, particularly via the Chinese language messaging app WeChat.
Fred Nile's Christian Democratic Party was behind the Chinese language messages, which urged voters not to vote Labor because Labor and the Greens wanted to legalise same-sex marriage within 100 days, and claimed the "gay movement" was targeting their kindergarten children.
The WeChat messages directed voters to preference the Liberals second behind the CDP.
A CDP spokesman said the messages didn't carry the CDP authorisation because they had been created by "passionate supporters" from Chinese Christian churches.
"They are worried about losing religious freedom, and changes to marriage, and the Safe Schools threat to children and even preschoolers," the CDP spokesman said.
The Facebook page of the CDP candidate for Reid, Peter Kang, carried messages claiming Safe Schools was linked to paedophilia.
Another WeChat message said Labor would bring 30,000 illegal migrants into Australia and there would be no places for Chinese families.
Labor didn't expect to win back Reid from first-term Liberal MP Craig Laundy.
But Barton remained a tight battleground, before booths closed. With a Liberal incumbent Nick Varvais, the seat had become notionally Labor on a boundary change, and was being contested by the high-profile former NSW Labor deputy leader Linda Burney.
The Turnbull family's yum cha excursion to Hurstville in the final days of the campaign, with granddaughter Isla in tow, was chosen to straddle the boundary of Chinese communities in Barton and Banks.
Labor said the Chinese community in Kingsford-Smith and Parramatta had also received the WeChat messages, but these seats were expected to hold for Labor.