Andy Meddick's daughter Kielan was attacked on a Fitzroy street on Thursday night and suffered a head injury, in what he believes was a politically-motivated incident.

The Animal Justice Party MP says the assault may be linked to his support for the state's proposed pandemic laws currently before state parliament.

Police say the 25-year-old woman was spray painting over a poster on Smith St about 11pm when a man approached her.

After an argument, she threw the can towards him while attempting to leave. He then followed her and threw it back, striking her in the back of the head.

But Mr Meddick told ABC Radio Melbourne the statement from police doesn't contain all the facts "for whatever reason" and maintained his daughter was not the instigator.

"That is patently untrue," he said.

Ms Meddick, who is an artist and transgender, came across an anti-vax sign on a pole and began spray painting over it when she was "aggressively and abusively" approached from behind.

She became "scared and started to walk away", her father said, and threw the can while running away from the man.

"She was worried that they had been identified because of (being my child)," Mr Meddick said, despite saying he didn't believe the man mentioned the MP's name.

"That's something that can only be determined if they catch the perpetrator and ask them."

His daughter posted on Instagram that the man had assaulted her for being "political", and later clarified she threw the can out of fear before he used it to attack her.

She said she has a three-centimetre gash on her head, which required stitches and glue.

Ms Meddick ran into the 86 Bar, where the staff treated her wounds before she was taken to hospital.

Manager of 86 Bar Anthony Wallace told AAP the venue supervisor heard a commotion before a woman lunged in the front entrance, screaming "he's going to kill me".

Mr Meddick said he has been "desperately worried" about "comments, threats and intimidation" that have been made against his family, staff and colleagues since he announced his support for the government's pandemic bill.

"My worst fears have been turned into a reality," he said.

Last week, Mr Meddick revealed protesters had targeted his house.

"It's a genuine fear ... that we will see re-enactments of what has occurred in the UK where MPs are actually killed," he said at the time.

The prime minister said his thoughts were with Mr Meddick and his family.

"This is not just an attack on an innocent person but an attack on our very democracy," Scott Morrison said in a Twitter post.

"I join with all Australians in unequivocally condemning these actions."

Premier Daniel Andrews also offered his support to Ms Meddick and her family in a post on Twitter.

"Violence of any form, for any reason, against any person has absolutely no place in Victoria," he said.

The Victorian government's bill, which gives the premier and health minister the power to declare a pandemic and issue health orders, has become a lightning rod for anti-lockdown and anti-vaccination groups.

It's been reported figures associated with the neo-Nazi movement have joined the protests on the steps of parliament.

A crowd staged a mock execution of the premier using wooden gallows on Monday evening, while another demonstrator attended an earlier protest with three nooses, in an apparent reference to crossbenchers who have supported the bill.

Australian Associated Press