Protesters face-off in Sydney CBD

On either end of Martin Place, separated by a wall of police, anti-racist and anti-Islam protesters have faced off near the scene of last year's Lindt Cafe siege.

On the lower end braving the rain on Saturday were vocal supporters of Reclaim Australia, a group pushing nationwide rallies against "sharia law, halal tax and Islamisation".

Many of the flag-waving crowd-goers, in the hundreds, chanted "Aussie, Aussie, Aussie - Oi, Oi, Oi" and were carrying home-made banners denouncing sharia law.

But it was a proposition those in the anti-racist rally corner labelled absurd.

"There is no possibility of sharia law in Australia, that is absolutely ridiculous," Tony Iltis said.

Mr Iltis was part of a smaller but passionate crowd that slammed Reclaim Australia's "racist" slant.

"Basically they are neo-nazis who are able to not look like neo-nazis because the mainstream has become so racist," Mr Iltis said.

"I think the Muslim community needs to know that not all Australians are racist. I think they feel intimidated and how the Jews felt in the 1930s."

Tensions almost erupted when a woman ran on stage at the Reclaim Australia camp, grabbed the microphone and told the crowd they should be ashamed.

Riot police were quick to respond and quell any clashes.

Among the Reclaim Australia crowd, many sporting Australiana memorabilia, was Greg and his home-made sign that compared sharia law to pedophilia.

"I'm just standing up for our freedom of speech and way of life," he said, wearing a green and gold shirt.

Rally organisers deny Reclaim Australia is racist, but say protesters have a problem with Islamic extremists who want to live by sharia law.

Event organiser Sarah Spearpoint says, like her, moderate Muslims also don't accept extreme views of their religion.