SYDNEY, Australia — The police in Tasmania have charged a man with assault after former Prime Minister Tony Abbott said in an interview that a same-sex-marriage supporter had head-butted him Thursday in Hobart.

According to a statement from the Tasmania Police, the man, whose name was not released but who was described as 38 and from North Hobart, was charged with one count of common assault and granted conditional bail. He will appear at Hobart Magistrates Court on Oct. 23, the police said.

Mr. Abbott first described the encounter to 2GB a Sydney radio station: He had been meeting with a local newspaper about his opposition to same-sex marriage, the subject of a nonbinding vote by mail now underway in Australia. As Mr. Abbott walked to his hotel, a man wearing a “Vote Yes” badge yelled his name.

“He says, ‘I want to shake your hand.’ I went over to shake his hand. Then, he head-butted me,” Mr. Abbott said. “Now, he wasn’t good at it, I’ve got to say, but he did make contact.” The exchange left him with a minor swollen lip, he said.