A man accused of planning terror attacks in Melbourne was just pretending in order to expose a police conspiracy against right-wing groups, his lawyer has told a court.

Key points: Phillip Galea believed police were allowing the "left" to become violent, his lawyer said

Phillip Galea believed police were allowing the "left" to become violent, his lawyer said She said he believed informers had been embedded in right-wing groups

She said he believed informers had been embedded in right-wing groups Mr Galea's lawyer said he devised a fake plan but was not a terrorist

Phillip Galea, 34, is on trial accused of plotting terrorist attacks on Trades Hall in Carlton, The Melbourne Anarchist Club in Northcote and the Resistance Centre in the city.

He is charged with committing "acts in preparation for, or planning a terrorist act" and attempting to make a document likely to facilitate a terrorist act.

Today, lawyer Felicity Gerry QC opened his defence by saying Mr Galea was not a terrorist nor was he planning an attack.

"He's not a terrorist. He's not part of any extremist group," Ms Gerry told the Supreme Court of Victoria.

She said Mr Galea was opposed to Islam, including halal practices and sharia law, and also hated left-wing groups.

She said he joined the right-wing movement Reclaim Australia and for a period of time was the lead organiser of its Victorian chapter.

Mr Galea believed Islamic extremism was on the rise and Muslims were responsible for terrorism in Australia and around the world, Ms Gerry said.

Prosecutors allege Trades Hall in Carlton was one of Mr Galea's targets. ( ABC News: Rudy De Santis )

He also thought that the "left" was becoming increasingly violent and that authorities were allowing it to happen.

He took on an "informal" role as an investigative journalist looking into "left-wing anarchy" and "Muslim extremism", Ms Gerry told the court.

Mr Galea attended a protest against a mosque at Bendigo and organised a rally opposing a Muslim school at Melton.

Ms Gerry said Mr Galea believed police had embedded an informer or "mole" inside right-wing groups as part of a left-wing scheme to bring them down.

She said Mr Galea wanted it to appear like he was planning a terrorist attack because if it got back to police, the suspected conspiracy would be confirmed.

"He devised a fake plan which will expose the police informer he believed to be active in right-wing groups," Ms Gerry told the jury.

Sometimes he would exaggerate in phone calls to convince people that the plans were real and not fake, she said.

The prosecution alleges he was preparing a how-to document for terrorism and researched about making bombs.

On Tuesday, the prosecution told the court Mr Galea told people he wanted to cut the throats of people in the CBD and create a "line of dead lefties".

The trial continues.