Anger erupts over rainbow noose ad

Australian anti-gay-marriage group Marriage Alliance has depicted a woman with a rainbow noose around her neck in its latest internet campaign.

The group is claiming that same-sex marriage will increase suicide because people who are against it will be bullied over their views if it becomes law.

The group posted an advertisement on social media saying "same sex marriage increases PC bullying in the workplace", with a picture of a sad-looking woman with a rainbow-coloured noose around her neck.

Mental health advocacy group beyondblue tweeted to the group and condemned them for their "harmful" message.

"@MarriageAll we're advocating strongly in this space to reduce stigma & harmful messages around suicide like this," their tweet said.

"You may not have thought about it, but you may want to consider the harm that depicting someone in a noose may cause."

Social media has erupted with thousands of angry comments, many calling the group out for their lack of evidence.

"This is sick. You can't come up with a real argument to support your nasty hate so you resort to this hateful fantasy. Shame," David Fowles wrote.

* Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14 or Suicide Call Back Service on 1300 659 467.