Iranian women and girls gather ahead of the 40th Islamic Revolution anniversary.
Iran's Guardian Council said Saturday it sent a bill that would allow Iranian mothers married to foreigners to confer citizenship on their children back to parliament, citing "security" concerns.
In a statement on its website, the council said it did not have an issue with the spirit of the bill, but rather the absence of any clauses allowing authorities to address "security" issues potentially arising from the activities of foreign fathers.
The council -- made up of clerics and jurists -- was also concerned that the bill planned to automatically grant residence permits to foreign fathers, when in the council's view the government must retain discretion to refuse, MP Tayebeh Siavoshi told the semi-official ISNA news agency.
The bill, overwhelmingly passed in May by parliament, has been seen as a huge step forward for thousands of children born in Iran to Afghan fathers who cannot enjoy full social rights.
Iran is one of seven countries worldwide that "do not allow mothers to confer their citizenship on their children with no or very limited exceptions," according to a 2019 report by the United Nations' refugee agency (UNHCR).
The next step is for parliament to review the bill and amend it, ahead of further discussion by the Guardian Council.
Parliament's powers are limited compared to other institutions.
Lawmaking is vetted by the Guardian Council, which has the authority to interpret the constitution and check laws' compliance with sharia.
According to Iranian officials, the Islamic republic is home to some three million Afghan immigrants, many of whom are married to Iranian women and have children.
"Thousands of children were left out in the cold... with this law things would have cleared up for them," said sociologist Mohammad Reza Jalaeipour in an interview with official news agency IRNA.
"Some of them can't have driving licenses, some of them can't have social security," he added.
*This story was edited by Ahram Online