Just one year after marriage was redefined in Colombia, three gay men have successfully gained legal recognition for a threesome “family”, sparking warnings it would be difficult to resist this in Australia. 

ACL managing director Lyle Shelton said the Columbian case demonstrated the logical consequences once legislators abolished the gender diversity requirement of the Marriage Act.

“As we have seen in Columbia, redefining marriage for one group will lead to calls from other groups for further redefinition,” Mr Shelton said.

“If marriage is solely about love, then it follows that people in all kinds of relationships may demand the right to be married.

 “Advocates for redefining marriage continue to assert that same-sex marriage will have no consequences and that there is no slippery slope.

“This is why we need a plebiscite. The Australian people should be allowed to assess all of the consequences of redefining marriage and then cast a vote in the privacy of the ballot box away from the intimidation of the rainbow political lobby,” Mr Shelton said.

More than 34,000 people have so far signed an ACL petition calling for a People's Vote.