Liberals and Labor have accused each other of dirty campaign tricks as the tight by-election race for Bennelong intensifies in Sydney.

Prime Minister Malcolm Turnbull on Wednesday admitted his party bought the domain of Labor's high-profile candidate Kristina Keneally.

The domain name kristinakeneally.com was purchased by the Liberal Party on the day the former NSW premier announced her candidacy in mid-November.

Smears and criticism was uploaded to the website on Wednesday with Mr Turnbull, campaigning in Bennelong alongside Liberal candidate John Alexander, subsequently defending the tactic.

"Kristina Keneally failed the people of NSW and she can't object to the facts of her record being raised," he told reporters in Macquarie Park.

And on the other side, the Alexander campaign claims a video distributed by Labor had been doctored to change what the Liberal candidate said regarding education and training funding.

"I find it the most despicable tactics, to not tell the truth," Mr Alexander said in a statement.

Ms Keneally accused the prime minister of "acting like a fool" by endorsing the domain name purchase.

"He doesn't have anything to offer the people of Australia," she told reporters at Ryde Hospital while campaigning with federal Labor leader Bill Shorten.

Mr Shorten accused Mr Turnbull of "being obsessed" with Ms Keneally and attacked his sense of entitlement.

"Just how up himself is he, Turnbull?" the opposition leader said.

"He seems to think the only person who's allowed to be prime minister is a person called Malcolm Turnbull."

The prime minister also doubled down on his criticism of disgraced Labor Senator Sam Dastyari's questionable dealings with Chinese political donors.

Ms Keneally accused Mr Turnbull of running a One Nation inspired "China-phobic" campaign, saying the large proportion of Chinese voters in the electorate are "alarmed."

But local Chinese business owners and workers on Wednesday told AAP they weren't fussed by the prime minister's rhetoric.

Susan Ha, a travel agent in Eastwood, said most people she knew were concerned with the tax rate for small businesses rather than the political games between the major parties.

"People care a lot for tax ... I think they still support the Liberals," Ms Ha said.

Another worker, who did not want to be named, believed local issues will be at the forefront of Chinese voters' minds at the ballot box on Saturday.

"What they can do for the community is what's important here for the Chinese," she said.

"The people here won't worry about the international relationships."

However, an online poll run by local Chinese newspaper Sydney Today showed Ms Keneally was the more popular of the two candidates.

Around 68 per cent of the more than 250 people who've taken part in the survey say they'll vote for the high-profile Labor candidate.

The government stands to lose its one-seat majority in the lower house if Mr Alexander is defeated.

The Liberal party's primary vote has collapsed in Bennelong with a Newspoll published this week suggesting Labor and the Liberals are 50-50 on a two-party preferred basis.