The Association of Combattant Clerics issued a statement saying that "if urgent measures are not taken to settle the current problem, which prevents free competition between legal political views, there is no further reason for the Association to take part in the parliamentary election," the reports said.

The statement was issued after a party meeting on Sunday attended by both the president and the speaker of the Majlis, or parliament, Mehdi Karoubi, who is also a member.

Iran has been thrown into crisis since the powerful Guardians Council, a conservative-dominated body, announced that it was barring a large number of reformist candidates from standing in the February 20 election.

The Association of Combattant Clerics groups reformists among Iran's Islamic rulers and emerged from a split in 1988 in the Association of Combattant Clergy, which is now pro-conservative.

At its meeting Sunday the association thanked Iran's supreme leader Ayatollah Ali Khamenei, whose "directives can fully resolve the problem" sparked by the Guardians Council action.

On Wednesday Khamenei called on the Guardians to review the cases of the invalidated candidates, which it has pledged to do, but the dispute is far from settled.

The Council, which screens all legislation and candidates for public office and also has to validate the election result, barred nearly half of the 8,000 who registered to stand on political and theological grounds.

Supporters of Khatami, including some 80 sitting MPs seeking re-election, were among the thousands on the blacklist.

The Majlis deputies affected began a sit-in at parliament on January 11 and on Monday they entered the third day of a protest fast.

Mohammad Jahromi, spokesman for the central election monitoring commission, which answers to the Guardians, said the review process had begun and already some originally rejected candidates, whom he did not identify, had been approved.

According to the reformist-headed interior ministry, some 1,220 candidates were turned down for non-respect of Islam and more than 1,370 others because there was no proof they were up to the job.