Parliament approved legislation on Tuesday requiring Russians to declare dual citizenship or face criminal prosecution after President Vladimir Putin endorsed the measure as part of a more nationalist course taken since his annexation of Crimea.

Adopted in the crucial second of three readings in the lower house, the bill will impose a fine of up to 200,000 rubles ($5,800) or 400 hours of community service on Russians who have citizenship in another country and fail to tell the authorities.

Critics said the law would place people with two passports under suspicion and expressed fear its aim was to whip up nationalist fervor by suggesting that dissenters are in the service of foreign governments.