The protesters blocked the entrance of the marina where those attending the fundraiser began meeting at 5.30pm.

They surrounded a bus on Marine Parade that was due to transport the Q Society supporters to an undisclosed location where the fundraiser was being held.

Some protesters rocked the bus, while others jostled Q Society supporters as they tried to board.

One man grabbed another man by the throat in the fracas.

More protesters held signs and shouted slogans including, "Racist, sexist, anti-queer Cory is not welcome here".

"As long as we can all get off safely with our views expressed, I'll be happy," said a Q Society member, who declined to give his real name.

At 7pm, protesters allowed the bus to depart with about 10 people on board. They continued protesting as they left the marina, chanting as they walked along Marine Parade.

Police were at the scene, but stayed at a distance. That appeared to be a tactical move, so as not to further ignite the protest.

Secrecy surrounded the fundraiser, with guests forbidden from knowing the location ahead of time.

Somehow, protesters got wind of the arrangements. By mid-afternoon, far-left activists were circulating details of the meeting point, and urging supporters to head down to the marina to "Reclaim St Kilda".

Liberal Party defector Bernardi and LNP MP George Christensen, who remains in the Turnbull government tent, were billed as the star attractions at the "Halal Choices" dinner in Melbourne.

The dinner - part of a two-night fundraising tour billed as "Defending Freedom of Speech" - was held to raise money for the legal defence bill of Kirralie Smith, one of the Q Society's most high-profile leaders.

Ms Smith is being sued for defamation by Halal certifier Mohamed El-Mouelhy, over videos she made about halal certification practices.

Q Society frames the case as an attack on free speech and estimates the defence bill will be $1 million.

The first fundraising dinner was held in Sydney on Thursday night, where guests - including cartoonist Larry Pickering - made homophobic and anti-Muslim comments.

Fairfax Media was invited to attend the fundraiser in Melbourne, but late on Friday, the official invitation was rescinded: organisers were apparently unhappy about an article published describing what was said at the Sydney dinner.

Pickering, who was a VIP guest at the Sydney fundraiser, made clear his views on Muslims.

"Let's be honest, I can't stand Muslims," he said.

"If they are in the same street as me, I start shaking."

Pickering, who had donated for auction one of his own works depicting the rape of a woman in a niqab by her son-in-law, later added: "They are not all bad, they do chuck pillow-biters off buildings."

With Jaqueline Maley