Iraqi Shiite cleric Moqtada al-Sadr warned on Thursday that members of his bloc will quit parliament if he is thwarted from forming a national majority government.
He made his remarks days before the deadline he set to his rival Shiite pro-Iran Coordination Framework to reach a solution to the country's political impasse.
In a televised speech, Sadr said he was ready to join the country's opposition if the deadlock were to continue.
The deadlock is "deliberate," he charged, saying his MPs should prepare their resignation letters because the Framework was continuing to impede the government formation efforts.
Sadr's latest warning is the starkest since the eruption of the crisis erupted in wake of the parliamentary elections that saw the influential cleric emerge as the clear winner with 75 MPs. The Framework has challenged the results, dismissing them as a sham.
Sadr has since formed a coalition with Sunni and Kurdish MPs to form a comfortable majority bloc in parliament.
As the Framework demonstrated it was unwilling to help form the government, Sadr announced he would grant them three months to form one and yet, no progress has been made. The deadline ends soon.
"If the Sadrist bloc is seen as an obstacle in the formation of a government, then they are ready to quit," Sadr declared on Thursday.
Parliament went into recess on Thursday and will convene again in July. It seems unlikely that that will be enough time for the deadlock to be resolved.
Observers have expressed alarm at Sadr's latest announcement, with some viewing it as a sign that he has no solution to ending the impasse.
It will also leave his Sunni and Kurdish allies at a loss over what position they will make in wake of his dramatic announcement.