Iraq’s judiciary suspended work on August 23 after supporters of powerful Shia cleric Moqtada al-Sadr camped out near its headquarters to demand that it dissolve parliament, escalating one of the worst political crises since the U.S.-led invasion.

The populist leader has helped inflame tensions in Iraq in recent weeks by commanding thousands of followers to storm and occupy parliament, preventing the formation of a government nearly 10 months after elections.

Prime Minister Mustafa al-Kadhimi, who cut short a trip to Egypt to deal with the crisis, has urged all sides to calm down and renewed calls for a national dialogue.

In a statement, Mr. Kadhimi said disrupting the judiciary “exposes the country to serious risks”.

Mr. Sadr’s Shia Muslim followers began gathering for protests outside the headquarters of the Supreme Judicial Council and Federal Supreme Court in Baghdad. They have sent threats by phone, the judiciary said in a statement.

“(We) will suspend court sessions as a protest against this unconstitutional behaviour and will hold the government and political parties which are backing this move fully responsible for all the results,” the statement added.

The standoff in Iraq is the longest stretch without a fully functioning government in the nearly two decades since Saddam Hussein was overthrown in a U.S.-led invasion in 2003.

Mr. Sadr was the biggest winner of the 2021 election but was unable to form a government along with Kurdish and Sunni Muslim Arab parties, excluding his Iran-backed Shia rivals.

The young cleric, who has unmatched influence in Iraq, can quickly mobilise hundreds of thousands of followers to stage demonstrations and paralyse the country’s byzantine politics.

Mr. Sadr, who fought U.S. troops and went on to become a kingmaker in Iraqi politics, has called for early elections and unspecified changes to the constitution after withdrawing his lawmakers from parliament in June.

“The people are demanding the parliament to be dissolved and the immediate formation of an interim government,” said a protester draped in an Iraqi flag.

“Help us. Stand with us. Don’t be afraid of anyone,” said another demonstrator.

Mr. Sadr’s political opponents, mostly fellow Shias backed by Iran, have refused to accede to his demands, raising fears of fresh unrest and violence in a conflict-weary Iraq.

He survived upheaval in the 19 years since his Mehdi Army militia took on the Americans with assault rifles and rocket-propelled grenades in the streets and alleys of Baghdad and southern cities.

His followers also fought the Iraqi army, Islamic State militants and rival Shia militias.

Most of Iraq’s Shia political establishment remains suspicious or even hostile to Mr. Sadr. Still, his political organisation, the Sadrist movement, has come to dominate the apparatus of the Iraqi state since the 2018 election, taking senior jobs within the interior, defence and communications ministries.