Thailand's Prime Minister Srettha Thavisin said on Tuesday that the cabinet has approved a draft law on marriage equality and that it would be brought to parliament during a session starting in December.
Thailand has one of Asia's most open and visible lesbian, gay, bisexual and transgender communities, but many political activists say Thai laws and traditional institutions have yet to reflect changing social attitudes and still discriminate against LGBT people and same-sex couples.
If the draft law is approved by parliament and receives royal assent, Thailand would become the third place in Asia after Taiwan and Nepal to recognise same-sex marriage.
Parliament last year debated four laws including civil unions for same-sex couples and marriage equality, but did not come to a final vote before the session ended.
The ruling Pheu Thai party and its rivals both campaigned ahead of this year's May elections on supporting marriage equality.
Srettha has also previously said he wants Thailand's capital Bangkok to host World Pride events in 2028.