A clash between Nepal’s government and its head of state over controversial citizenship legislation threw the nascent republic into turmoil on Wednesday, after President Bidhya Devi Bhandari refused to sign proposed amendments in the law.

The bill proposed, among other changes, to give citizenship certificates to children whose parents’ whereabouts were not known. Under the amendments, children born to a Nepali mother but whose father is unknown could get citizenship documents after the mother makes a declaration. The changes would have entitled more than 500,000 people to citizenship certificates and eventually given them voting rights.

It would also give citizenship documents to Nepalis who are citizens of foreign nations to do business and conduct economic activities in the country. The deadline for Bhandari to approve the amendment to the 16-year-old Nepal Citizenship Act, expired at midnight. “Since the government and parliament did not address her concerns, the President has refused to approve the bill,” Bhesh Raj Adhikari, an aide to Bhandari, said.

Experts said the President was required to approve the changes. The ruling alliance said the President had deprived many Nepalis of their right to citizenship by failing to approve the bill.