Crisis for Iraq govt after Sunni bloc quits-dep PM

BAGHDAD, Aug 1 (Reuters) Iraqi Prime Minister Nuri al-Maliki's 15-month-old Shi'ite-led government is facing its biggest crisis after the main Sunni Arab bloc withdrew its ministers today, Deputy Prime Minister Barham Salih said.

''This is probably the most serious political crisis we have faced since the passage of the constitution. If unresolved the implications are grave,'' Salih, a Kurd, told Reuters.

Negotiations on Iraq's new constitution, adopted in a referendum in October 2005, were notoriously difficult, with much effort spent by U S officials and others on convincing Sunni Arabs to take part in the poll and the national elections in December 2005 that brought Shi'ites to power.

REUTERS RN HT1715