Shia Iraqis have marched in support of Moqtada Sadr
Iraq's prime minister has threatened to exclude the supporters of radical cleric Moqtada Sadr from politics.
Nouri Maliki told CNN that the cleric's movement would not be allowed to take part in elections unless it disbanded its militia, the Mehdi Army.
The prime minister and major Iraqi parties had already called for militias to be dissolved as the government waged a security campaign against the groups.
But it was the first time that Mr Maliki had singled out the Mehdi Army.
Aides to Moqtada Sadr on Monday said he would disband the militia if senior Shia religious leaders ordered him to do so.
They said a delegation would be sent to discuss the issue with the top Shia cleric in Iraq, Grand Ayatollah Ali al-Sistani, and a grand ayatollah based in Iran.
In his interview, Mr Maliki said: "A decision was taken... that they no longer have a right to participate in the political process or take part in the upcoming elections unless they end the Mehdi Army.
"Solving the problem comes in no other way than dissolving the Mehdi Army."
The provincial elections are scheduled for later this year.
Mr Maliki took power with the help of Moqtada Sadr, but broke with the cleric last year.
The BBC's Adam Brookes in Baghdad says the confrontation between the two men is growing.
Two weeks ago the prime minister sent thousands of troops into the city of Basra to try to force the Mehdi Army into submission.
The militia withdrew from the streets, but the operation was inconclusive.
Mr Maliki said the government would continue the crackdown. "We have opened the door for confrontation, a real confrontation with these gangs, and we will not stop until we are in full control of these areas," he said.
An MP for the Sadr bloc, Liqaa Aal Yassin, told the BBC Arabic service that two delegations would be sent - to Grand Ayatollah Sistani in Najaf and Grand Ayatollah Kazem al-Husseini al-Haeri in Iran - to discuss the possible disbanding of the Mehdi Army.
Ms Yassin said the government was also sending a delegation to Moqtada Sadr to discuss Mr Maliki's demand.
Mr Maliki's comments came after heavy fighting between US and Iraqi forces and the Mehdi Army at the weekend.
At least 22 people were killed and more than 50 others injured in clashes in the capital's eastern district of Sadr City, a stronghold of the militia.
Five US soldiers were killed, including three who died during rocket and mortar attacks in Baghdad.
Two of those died in attacks on the heavily-fortified Green Zone.
Moqtada Sadr has called for a mass demonstration on Wednesday against the US military presence.