Labor has accused Liberal volunteers of using racially charged language against some of its volunteers who were speaking Mandarin and Cantonese at a polling booth in the marginal Sydney seat of Reid.

Labor's Reid candidate Sam Crosby told SBS News he has lodged a complaint over two alleged instances he witnessed of Liberal volunteers using racist language at the Concord pre-polling station.

In one case, he said a volunteer was explaining the Senate ballot to a voter in Cantonese when a Liberal volunteer "stormed over" and said "very loudly and very rudely 'English only, you are not allowed to speak their language'."

AAP

In another, Mr Crosby said a Liberal volunteer asked a Chinese-Australian Labor volunteer: "How long have you even been in Australia?"

The individual questioned was an Australian citizen and had been in the country for decades.

Mr Crosby said he has lodged a complaint with electoral officials at the pre-polling station.

SBS News understands Liberal volunteers have also lodged complaints as tensions remain high at two pre-polling booths.

Police are investigating an incident at the Ashfield pre-polling booth where Liberal candidate Fiona Martin was allegedly "manhandled" and "bullied" by an aggressive volunteer last week.

AAP

'Ongoing low-level racism'

Nearly one in five residents in the electorate of Reid have Chinese heritage and they will be crucial to deciding the result of the seat, held by the Liberals by a margin of 4.7 per cent.

Mr Crosby said he'd had enough of the regular "low-level racism" on display in the campaign.

"This sort of ongoing, low-level racism that just boils along in the background with some of these people, it's frustrating."

While he understood polling places "often get a bit boisterous, a bit intense", he said these insults were different.

He said one of his volunteers had told him he was called a "dickhead" by a Liberal volunteer for speaking Mandarin to a voter.

"None of the white, Caucasian volunteers have ever had had anything like this said to them.

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"I genuinely do hope this is limited to a few bitter individuals ... but I want to call it out."

In response to the claims, Liberal candidate Fiona Martin called on all sides to show respect and tolerance.

"Election campaigns should be about policy and our vision for the future and I have always made clear to my volunteers that all participants in the campaign should be respectful and tolerant.

"And I call on my Labor opponent to ensure his volunteers do the same."

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