The three — Falah al-Sawwagh, Bader al-Dahum and Khaled al-Tahus — were questioned for nine hours on accusations of undermining the status of Kuwait’s ruler before being taken into custody around midnight, defence lawyer Mohammad al-Jumaih said.

Emir Sheikh Sabah al-Ahmad Al-Sabah will give a televised address to the nation at 1700 GMT Friday, the royal court announced without providing details about the previously unscheduled speech.

The prosecutor also extended the detention for three more days of four opposition activists arrested on Monday during clashes between police and protesters following a huge rally.

The move came as hundreds of supporters of the Islamist and nationalist-led opposition and former lawmakers gathered outside the Palace of Justice in the capital, Kuwait City, in solidarity with the ex-MPs and activists.

Local media and activists said more arrest orders will be issued soon against several former lawmakers including outspoken opposition leader Mussallam al-Barrak on the same accusations. The opposition leaders are being summoned for speaking at three rallies held this month to protest an alleged government plan to amend the electoral law to manipulate election results.

Breaking decades-old taboos, speakers directly addressed the emir, warning him that any amendment to the electoral law could lead to street protests and chaos. They also warned Kuwait was becoming an autocratic state, and insisted they would oppose that.

The emirate embraced parliamentary democracy half a century ago, but it is illegal under the constitution to criticise the emir who enjoys extensive authority and must be from the Al-Sabah ruling family, in power for more than 250 years.

“The detention of the former MPs is an unwise decision ... It will only fuel tensions in the country and instigate more protests,” former Islamist lawmaker Mohammad Hayef warned on his Twitter account.

Waleed al-Tabtabai, another former MP, criticised the government’s policy of clamping down on the opposition and arresting its leaders, insisting that what they said at rallies was “allowed criticism aimed at reforms.”

Kuwait, an OPEC member which says it sits on 20 percent of global oil reserves and has more than $400 billion of surpluses, has been in a virtual limbo since June 20 when the top court annulled an opposition-dominated parliament.

The historical court verdict also reinstated the pro-government parliament elected in 2009 after it was dissolved in December following street protests and corruption allegations.

The house however was dissolved again two weeks ago but the government has so far failed to set a date for next elections amid allegations it is planning to change the electoral law to manipulate the polls results.

The Gulf state has been rocked by a series of political crises since 2006 during which the government resigned nine times and parliament was dissolved on six occasions, five of them by the emir and one by the courts.