Three countries are in a neck-and-neck race to become the second South American nation to legalise same-sex marriage.
Colombia’s Constitutional Court ruled in July that Congress must legislate before June 20 2013 or marriage rights would be automatically granted to same-sex couples.
The Colombian Liberal Party and the Alternative Democratic alliance have drafted bills to legalise same-sex marriage. The Social Party of National Unity and the Colombian Greens have both drafted civil unions bills.
In Uruguay, a bill to legalise same-sex marriage was submitted to Parliament on September 6.
In Brazil, judges have been converting civil unions into legal marriages since June. Legislators are yet to pass national laws that would properly regulate the process for same-sex couples.