Phillip Galea, 31, was charged on Thursday with possessing five Tasers and possessing a quantity of mercury following a raid on his Braybrook home.

During an appearance before Melbourne Magistrates Court on Friday to plead guilty to the charges, magistrate Jonathan Klestadt was told Galea was a member of Reclaim Australia and not linked to the United Patriots Front.

Mr Klestadt quoted Monty Python's Life of Brian in response: "Whether it's the Peoples Front of Judea or the Judean Peoples Front, it's all the same," he said.

"The aim of the group is to deflect or destroy the multicultural aspect of Australia," Mr Klestadt said.

"I don't for one moment suggest that you are anything other than a serious holder of that political view, which espouses the elimination or subjugation of other political, religious or ethnic groups to what
you believe to be the Australian way of life."

The court heard Galea was arrested in the lead-up to an anti-immigration rally in Melton scheduled for Sunday.

Senior Sergeant Paul Rudd, prosecuting, said police found the Tasers and a bottle of about 360 grams of mercury in Galea's home.

They also found information about making explosives on Galea's computer, the court heard, along with an "extensive" amount of "extreme" material linked with far-right groups.

Galea was remanded in custody on Thursday night and pleaded guilty to the charges on Friday.

The court was told he had previously been found in possession of a knife at a rally, and allegedly had a flare at a separate event in Bendigo.

Defence counsel Bill Grimshaw said there was no evidence Galea planned to use the Tasers or mercury - which can be used in the manufacture of explosives - for any "nefarious purpose".

Galea had been in possession of the Tasers because of previous threats to his safety because of his views, Mr Grimshaw said, and had thought the mercury might be useful in making electronic switches, as he is an electronics enthusiast.

He had come across the mercury while completing a cleaning job for a friend.

But Mr Klestadt found that because Galea had previously been in possession of weapons at anti-immigration rallies - he was fined for possessing the knife and a charge is outstanding over the alleged possession of the flare - he did not accept the defence submission of self-defence.

"Rather, I form the view it was for an aggressive attack on those in the community with whom you have a disagreement," Mr Klestadt said.

The magistrate jailed Galea for one month and fined him $5000 and told Galea many Australians would hold his extreme views offensive.

Mr Grimshaw earlier told the court Galea should not be punished for his beliefs no matter how "repugnant" they appeared to the court and community.

Galea, who has previous criminal convictions but had never before been in custody, told his lawyer after the sentence was passed that he was concerned about possible reprisals in custody given his views.

The magistrate acknowledged the concerns before Galea was led from the dock.