Chief justice Arief Hidayat said existing laws on adultery did not conflict with the constitution and that it was not the authority of the constitutional court to create a new policy.
“The plaintiff should submit their petition to lawmakers, and there it should be an important input in the ongoing revision of the national criminal code,” Hidayat said.
“Based on that view, the constitutional court is of the opinion that the petition is not legally sound.”
Indonesia’s parliament is currently deliberating revisions to the national criminal code.
The Southeast Asian country has seen a rise of a hardline, politicized Islam in recent years, which until recently had stayed on the fringe of the nation’s politics.
The petition put forward by the Family Love Alliance (AILA), a group of conservative academics and activists, called for the definition of adultery to apply not just to married couples but to anyone in a marriage or outside it - effectively making all sex outside of marriage a crime.
In their complaint, AILA said certain articles in the national criminal code “threaten the resilience of families and therefore of Indonesia itself.”
Some rights activists said the petition was partially aimed at criminalizing gay sex, which is currently not regulated by the law, except in the ultra-conservative province of Aceh and in cases of child abuse.
Additional reporting and writing by Kanupriya Kapoor; Editing by Simon Cameron-MooreOur Standards:The Thomson Reuters Trust Principles.