Iran's reformist president, Mohammed Khatami, praised the Islamic Revolution to cheering crowds, even as his government is struggling to overcome a bitter face-off with Islamic leaders.

Last month, the conservative Guardian Council blocked thousands of reformists from running in next week's parliamentary election, sparking mass resignations in government and indignation among many reformist politicians.

Voter support for reforms has been growing in recent years. President Khatami was elected by a near 70 percent majority in each of his last two terms, but his government has not been able to carry out reforms, which it promised.

Analyst Hassan Nafaa, a professor of political science at Cairo University, says conservative leaders, particularly the Guardian Council, are becoming more aggressive in defending their values.

"They perceive themselves as the guardians of the Islamic Revolution, and they perceive the liberals as people who might cross the Islamic red lines," said Mr. Nafaa. "Now, the conservatives have the impression they have to be even more conservative, in order to defend better the Islamic revolution in a very hostile environment."

Iran's Islamic theocracy wields far more power than elected officials. For instance, the Guardian Council, a 12-member body of Islamic clerics and jurists, is appointed by Iran's supreme leader, Ayatollah Ali Khamenei, and has the power to block legislation passed by the parliament, if it does not conform to Islamic principles.

But Iranian expert and professor of political science at Cairo University, Niveen Mossaad, says the recent conflict that has arisen between reformists and conservatives is very different from the discontent that drove the Islamic Revolution 25 years ago. She says that during the past 25 years, a new generation has grown up in Iran, one that did not go through the sufferings that led to the previous revolution, and is not as attached to Islamic values.

That generational detachment, combined with the inability of the reformists to stand up to the conservatives, analysts say, is partly to blame for low voter turnout and general disillusionment with politics among the voters.

But ties to Islam remain strong in Iran.

An expert on Iran from Cairo's Al-Ahram Center for Political and Strategic Studies, Fahmy Howeidi, says external influences, such as Washington's campaign for democracy throughout the Middle East, and U.S. support for reformist ideals, are having an impact on Iran's political dynamic.

"Now, in 2004, the whole situation has been changed, and the American presence in the area and the threat [it presents] to Iran, this changes the whole mood," he said. "In Iran, the Islamic Revolution is not only a political issue, it is a religious issue as well. The people may not be happy with the regime, but they think that, as good Muslims, they have to defend or support the regime. The political and the religious aspects can be contradictory. The people are loyal to the religion, but they are against the regime."

Analysts emphasize all of Iran's top leaders, including reformists such as President Khatami, come from within the Islamic Revolution and bringing radical change may not take place until a new, post-revolution, generation takes over.