A woman pictured at a peaceful rally supporting same-sex marriage alleges she's been defamed by "No" campaigners using her image on an about "violent" extremists.
A photo of Jill Moran, a 26-year-old from Canberra, holding a rainbow flag at a rally in August was used on the Coalition for Marriage website above allegations of violent protesting, extremism, bullying and intimidation.
Slater and Gordon lawyers say requests for the photo to be removed have been ignored and Ms Moran will pursue defamation action unless she gets an apology.
Ms Moran, 26, said she felt "sick to her stomach" when a friend pointed out how the image had been used.
"I am a passionate supporter of marriage equality and I am proud to campaign publicly, but it is completely untrue and hurtful to paint me as violent or a political extremist," she said in a statement on Tuesday.
"I am embarrassed and angry to be associated with anything other than peaceful campaigning."
But the Coalition for Marriage denies it has defamed anyone and says it was fighting for freedom of speech.
"That includes freedom of political communication," a spokeswoman told AAP in a statement.
The image showed Yes campaigners "brazenly disrupting a peaceful anti-Safe Schools event in Canberra," she said.
The media release quoted Coalition for Marriage spokeswoman Sophie York, who referred to the "bullying and intimidation tactics" at the base of the Yes campaign, along with its "loud, violent protests".
Slater and Gordon defamation lawyer Phil Johnston said the photograph remained online despite requests for it to be taken down and an apology issued.
An Australian Bureau of Statistics postal vote for marriage law is seen in Sydney, Sunday, 24 September, 2017. Source: AAP
Mr Johnston warned other people depicted in material issued by the group could also have been defamed.
The Coalition for Marriage said it had not referred to anyone by name, however defamation legislation also includes "indirect identification".
The group noted Ms Moran was a "seasoned political activist" and former Greens candidate who used the image as her Facebook profile picture.
It also claimed she had tweeted the image with a statement that she was "smashing the heteropatriarchy".
Under defamation law, the Coalition for Marriage has 28 days to adhere to Slater and Gordon's requests, which were issued on September 25.
