Kuwait's opposition Tuesday condemned a government decision to "revoke" the citizenship of nationals deemed to pose a risk to national security and called on the government to resign, AFP reported.
On Monday, the Gulf state's Cabinet ordered the Interior Ministry to review the citizenship of people "who undermine the country's security and stability" and vowed an "iron fist" policy in a crackdown on dissent following violent protests.
It also warned of penalties for non-profit organizations, including many Islamic charities, which involve themselves in politics.
"This is an invitation for security agencies to suppress peaceful protests by the opposition ... a threat to revoke citizenship and curb non-profit organisations," the leftist Progressive Movement said in a statement.
Riot police this month clashed with demonstrators protesting over the arrest and detention of prominent opposition leader Mussallam al-Barrak for allegedly insulting the judiciary.
Some 50 people were arrested, with most now out on bail.
"The Cabinet statement provides a blessing for the police state approach and for the security suppression of the people and opponents," former opposition MP Mubarak al-Waalan tweeted.
Bashar al-Sayegh, of the liberal National Democratic Alliance, said: "Revoking the citizenship of any Kuwaiti national is an act of aggression on humanity, especially if it was for a political or religious opinion."
The Progressive Movement and opposition figures called for the government to be sacked, parliament to be dissolved and fresh elections based on an old electoral law.
However, a member of the pro-government parliament hailed the Cabinet decision and urged speedy implementation.
"A big thanks to the Cabinet for its decisive and firm statement," Nabil al-Fadhl tweeted.
"But we warn that if this statement is not backed by swift actions to affirm the government's seriousness, it will backfire."
The new developments, triggered by allegations that former senior officials plotted a coup and stole billions in public funds, plunged the oil-rich emirate into new political crisis.
Since mid-2006, Kuwait has been rocked by a series of political crises, with around a dozen Cabinets and parliament being dissolved six times.
Most opposition groups are not represented in parliament after boycotting a July 2013 election in protest at an amended electoral law.