A Shia Islamist party formerly allied to Nouri al-Maliki, prime minister, withdrew from Iraq’s ruling coalition on Wednesday, declaring itself ready to join other groups to form a cross-sectarian alliance.

The move by the Fadila or Virtue party does not represent an immediate challenge to Mr Maliki’s government, whose United Iraqi Alliance is still the largest bloc by far in parliament and is in close alliance with the second largest, the Kurdistan Alliance.