BAGHDAD, April 7 (Reuters) - The movement of Iraqi Shi’ite cleric Moqtada al-Sadr will be barred from taking part in the political process and elections unless it disbands its Mehdi Army militia, U.S. television network CNN quoted Prime Minister Nuri al-Maliki as saying.

Maliki’s ultimatum will heighten tensions with Sadr’s movement and the Mehdi Army, which fought pitched battles with Iraqi security forces for six days late last month in violence that killed hundreds of people.

“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,” Maliki said in an interview with CNN, according to a report posted on the network’s website.

Provincial elections are due by October.

Iraq’s political leadership on Saturday called on all parties to disband their militias before the local elections, but they did not mention the Mehdi Army by name.

The statement, agreed by a body comprising the president, the two vice presidents, Maliki, and the heads of political blocs, was seen as an attempt to isolate the populist cleric, who has a wide following among poor, urban Shi’ites.

Sadr’s movement was the only bloc to reject the statement.

Fresh fighting between security forces and gunmen erupted in Sadr’s stronghold in Baghdad on Sunday, killing more than two dozen people.