(CNN)Former Australian Prime Minister Tony Abbott was allegedly assaulted while campaigning for a "no" vote in an increasingly divisive national survey over whether to allow same-sex marriage.
Former Australian PM Abbott 'attacked by same-sex marriage supporter'
Abbott was headbutted Thursday by a man wearing a "yes" badge in Hobart, Tasmania, the former leader told CNN affiliate Sky News.
Australians are being asked to cast postal votes on whether the law should be changed to allow same-sex marriage. They have until November 7 to return their forms.
"A fellow sung out at me, 'hey Tony,' I turned around, there was a chap wearing a Vote Yes badge," Abbott told Melbourne radio station 3AW.
"I went over to shake his hand then he head-butted me," he added, saying the assault left him with a "very slightly swollen lip."
Alex Greenwich, co-chair of Australian Marriage Equality, said on Twitter there "is absolutely no place for violence" in the debate over same-sex marriage, which is "about treating people fairly and with respect and dignity."
Fears the campaign could see a rash of inflammatory comments led the government pass a temporary law last week banning hate speech for the duration of the vote.
The new law threatens a $12,600 Australian ($10,000) fine for people who vilify, intimidate or threaten harm "on the basis of sexual orientation, gender identity, intersex status or religion."
Last week, a 48-year-old man was charged with assaulting the godson of former Prime Minister Kevin Rudd as the 19-year-old was campaigning in favor of marriage equality.
Other "yes" campaigners have been sharing homophobic abuse they have received online under the #TheyGetToVote hashtag on Twitter.
Speaking to 3AW, Abbott said there had been widespread "intolerance and bigotry" from "yes" campaigners.
Same-sex marriage advocates had tried to stop the vote partly because it would give opponents a platform to promote intolerant and hurtful messages to a national audience.
Polls have long showed a majority of Australians in favor of same-sex marriage, and supporters have called for parliament to change the law themselves.
The postal vote is voluntary and non-binding, meaning the government is not legally obligated to go along with it. If Australians vote in favor, Parliament still would have to pass legislation to make same-sex marriage law. The results will be announced on November 15.
A Catholic who once studied to be a priest, Abbott is a leading opponent of same-sex marriage. He was ousted as leader of the Liberal Party in September 2015 and replaced by current Prime Minister Malcom Turnbull, who is backing the "yes" campaign.
Abbott's sister and daughter have both prominently come out in favor of same-sex marriage, with the latter writing on Instagram last week "yes please" and "it's time."