The AMS issued a statement on Friday accusing the Americans of imposing unacceptable authority on the Iraqis, just as the former Iraqi regime did.
Paul Bremer threatened last week to use his veto should the interim Governing Council choose Islam as the main basis for legislation.
"Our position is clear, and the text that is in there now is as I say. It can not become law until I sign it," Bremer said.
Speaking to Aljazeera, spokesman of the Association of Muslim Scholars (AMS) Shaikh Muhammad Bashar al-Faidi said the new Iraqi constitution should be based on the main Islamic rules.
Al-Faidi has assured that Islam, as the main legislative reference, will guarantee the full rights of all Iraqi groups including the minorities.
"The majority of Iraqi groups are absolutely with us, and that is why US administrator Paul Bremer threatened to veto," al-Faidi said. "Bremer would not have threatened to veto if he was sure all Iraqi groups would be with him," he added.
"The United States has invaded Iraq claiming it would liberate it and achieve democracy. Why would it then exercise intellectual oppression against Iraqis, just like what the former Iraqi regime did?"
Shaikh Muhammad Bashar al-Faidi,
Spokesman of the Association of Muslim Scholars
"The United States has invaded Iraq claiming it would liberate it and achieve democracy," al-Faidi said. "Why would it then exercise intellectual oppression against Iraqis, just like what the former Iraqi regime did?" he added.
The Governing Council has been charged with writing the temporary constitution or fundamental law that will govern Iraq until national elections are held.
Many observers believe some council members are pushing to implement Islamist rule in the post-occupation era.
Bremer vowed the new law would protect civil liberties in line with the agreement he reached with the Governing Council last November that set 30 June as the final day of the US-led occupation.