Major opposition parties have submitted a bill that would permit same-sex marriage, a move that comes weeks after Taiwan became the first place in Asia to legalize gay marriage.

The bill, submitted Monday, is unlikely to go far in the Diet, where the ruling Liberal Democratic Party has barely budged to advance civil rights for LGBT people, even though business leaders have demanded change, saying current policies are hurting their ability to attract top global talent.

The bill by the Constitutional Democratic Party of Japan, Japanese Communist Party and others states that marriage would be established on the basis of marriage equality.

Neutral language would be adopted with the terms “party of marriage” used in place of “husband” and “wife,” while “father and mother” would be replaced by “parent.”

One problem faced by any possible law is Article 24 of the Constitution. It states: “Marriage shall be based only on the mutual consent of both sexes and it shall be maintained through mutual cooperation with the equal rights of husband and wife as a basis.”

Supporters have said this article is directed toward family registries and does not affect same-sex marriage, while opponents have said a constitutional change would be needed to allow same-sex unions.

Activists have argued that if there is no progress on same-sex marriage, it could become a source of embarrassment when Tokyo hosts the 2020 Summer Olympics. They have also brought challenges at court seeking change.

The public appears more tolerant than the LDP, which has controlled the government for all but four years since 1955. Homosexual relationships were long condoned among the samurai class and Buddhist monks before Japan’s mid-19th century modernization and adoption of “Western” values.

Same-sex couples in Taiwan celebrated their first gay marriages in late May, with the government enacting the law despite strong public opposition to gay marriage.