Liberal and conservative groups are doing battle in an island-wide vote that taps in to one of the island's most incendiary social issues. It's one of 10 referendums on Saturday on a raft of issues which are being held alongside local elections.
Taiwan's top court legalised same-sex marriage in May 2017, making it the first place in Asia to do so. The changes were to be implemented within two years but the government has made little progress on bringing them in as it came under pressure from conservative campaigners.
"Pro-family" activists have put forward three referendums calling for marriage to be legally defined as between a man and a woman, for a separate law to be enacted for same-sex unions, and for education on LGBT issues not to be compulsory in schools.
Although the government has made clear the referendum results will not impact the court's original decision, LGBT campaigners fear a defeat could mean their new rights will be more limited when they come in to force.
Pro-gay groups have brought two rival referendums calling for equal marriage rights and promoting education on gender equality -- including different sexual orientations.
"We are very nervous, it's like a tug-of-war war," said Jennifer Lu, a spokeswoman for the Marriage Equality Coalition which is backing the votes.
"We hope that love and equality will win," added Suki Chung, East Asia Campaigner at Amnesty International. "However, if the opposite happens then the government must not use the result as cover to water down same-sex marriage proposals."
Conservative campaigners accuse the court of making a political decision that did not take into account public views.
"We think the Constitutional Court's ruling has created more problems rather than resolving them," said Yu Hsin-Yi, spokesman for the Coalition for the Happiness of our Next Generation, adding he was "cautiously optimistic" about the vote.
A survey released by the Taiwan Public Opinions Foundation last week showed 77 percent agreed with the referendum proposal that a marriage should be between a man and a woman, with 65 percent against amending the current Civil Code to include same-sex unions.
If more than 25 percent of nearly 20 million eligible voters cast their ballot in favour, and providing the "yes" votes surpass the "no", the government must draw up a bill that reflects the results -- which then goes to a parliamentary vote.
Celebrities including famous Taiwanese dancer Lin Hwai-min have voiced support for the pro-gay referendums.
Local and international firms including Google and Deutsche Bank have also said they support full equality.
Conservative groups have created YouTube videos explaining their stance, while insisting they are not anti-gay rights.
Social media forums have been rife with posts arguing that allowing gay marriage would increase the number of foreigners with HIV coming to Taiwan to take advantage of its healthcare system.