A former mayor of Knox City Council, Mr Cossari claims the incident occurred at a pre-polling booth in Rowville on November 12, but concedes he is unable to provide witnesses to verify his account of the incident.

Mr Wells has emphatically denied any assault took place. His lawyer filed a statement of claim in the County Court of Victoria on December 21 seeking an apology, removal of the posts and damages.

According to court documents, the harm to Mr Wells' reputation was exacerbated by the sharing of the Facebook post and subsequent online comments made by Mr Cossari.

Carbone Lawyers managing partner Tony Carbone said he was unable to comment while the matter was before court, other than to say: "Mr Wells has done an enormous amount for the community and is the subject of a malicious personal attack. He wants a retraction of the comments and an unqualified apology to clear his good name."

Mr Wells served as the Victorian treasurer between 2010 and 2013 before becoming the police and emergency services minister under the former Baillieu/Napthine government.

He was re-elected last month with more than 50 per cent of the primary vote, while Mr Cossari secured just 5.3 per cent.

Mr Cossari told The Age he would defend the matter in court.

"If he wants to go down the defamation path that's fine, but I was manhandled and attacked and I have made a report to police," he said.

"I have nothing to gain from making up this story. I have played an honourable game all the way through."

On November 14, Mr Cossari made a statement at Rowville police station, which he also posted on Facebook.

The Age understands that police spoke with Mr Wells, but did not investigate the complaint further.