Opponents of Prime Minister Nouri al-Maliki have failed to muster enough support to bring him down in a vote of no confidence, Iraq's president said in a statement posted on his website Sunday.

Al-Maliki, a Shiite, faces a growing challenge from Sunni and Kurdish parties as well as other Shiites within his unity government who accuse him of monopolizing power.

But al-Maliki also has allies such as President Jalal Talabani, a Kurd, whose office must affirm that a petition for a no-confidence vote has enough signatures. Talabani's refusal to ratify the no-confidence campaign's letter is a setback for al-Maliki's opponents, although the constitution gives them other ways of trying for the vote.

Coalition rebels said in a statement they would keep trying to unseat al-Maliki and to "put an end to the monopoly (on power) and domination" by the prime minister.

Talabani has close ties to Iran, which has been using its leverage in Iraq to keep al-Maliki in place. Divisions among the prime minister's opponents may also be undercutting the no confidence push.