Updated

The Obama administration will remove from the U.S. terrorism list an Iranian militant group formerly allied with Iraqi President Saddam Hussein, officials said Friday, describing a move that will infuriate Tehran and end years of high-profile campaigning by the group.

Secretary of State Hillary Rodham Clinton will notify Congress of her intent later Friday, the officials said. A court order had given her until Oct. 1 to make a decision about the Mujahedeen-e-Khalq, or MEK. The officials spoke on condition of anonymity because they weren't authorized to speak about the matter.

Clinton's decision comes just days after the last big batch of the Iranian exiles reluctantly left their decades-old paramilitary base in northeastern Iraq, relocating for now to a refugee camp outside Baghdad. The U.S. had insisted that the MEK's 3,000 members comply with an Iraqi demand to leave Camp Ashraf as a condition of the MEK's removal from the list of foreign terrorist organizations.

Derided by its critics as a cult, the group has journeyed through multiple countries and the shifting alliances of the Middle East over its four-decade history. The MEK helped Islamic clerics overthrow Iran's shah before carrying out a series of bombings and assassinations against the Iranian government. It fought in the 1980s alongside Saddam's forces in the Iran-Iraq war, but disarmed after the U.S. invasion of Iraq in 2003. It has since suffered violent recriminations from Iraq's new Shiite-dominated government.

The decision to remove the MEK list rested on two factors: whether it still had the capacity and intent to commit acts of terror. Several American military officials and defense contractors were killed by the MEK in the 1970s, U.S. officials maintain, and its attacks have killed hundreds of Iranians. But the group contended it swore off violence more than a decade ago and now only seeks a peaceful overthrow of Iran's theocratic government.

The MEK assembled a high-profile roster of champions even as it remained on the U.S. blacklist. Luminaries who've advocated for the MEK's removal from the list include former Attorney General Michael Mukasey, former FBI Director Louis Freeh, former Homeland Security Secretary Tom Ridge, former Pennsylvania Gov. Ed Rendell and James Jones, President Barack Obama's first national security adviser.

That led the Treasury Department earlier this year to examine whether the officials were providing illegal material support to designated terrorists; that civil inquiry probably would be nullified now. Removal from the list also should make it easier for the MEK to raise money and recruit in the United States.

The organization is far from Iran's mainstream opposition, however.

The group has an ideology mixing Marxism, secularism, an obsession with martyrdom and near adoration of its leaders. A 2009 report by the security think tank RAND accuses it of fraudulent recruiting as well as "authoritarian control, confiscation of assets, sexual control (including mandatory divorce and celibacy), emotional isolation, forced labor, sleep deprivation, physical abuse and limited exit options."

MEK supporters say this is Iranian propaganda, pointing to several former members who've freely left the group.

It also vehemently rejects the Iranian accusation that members have worked with Israel to assassinate several Iranian nuclear scientists. U.S. officials say there is no evidence to suggest recent terrorist activity by the group.

U.S. officials said Clinton's letter to Congress would not amount to a final designation. That will probably come in a couple of weeks as officials unfreeze assets held by the group in the United States and other legal work that might allow it to open a U.S. office.

Camp Ashraf is not yet fully closed. An estimated 200 exiles remain there to try to sell off the property that was left behind in the move, but Iraq's government wants them to leave quickly.

The hostility of Baghdad's Shiite leaders reflect its desire to build stronger ties with Iran, but also the deep hatred for the group in Iraq because of its purported role in helping Saddam crush Shiite and Kurdish revolts in the 1990s.

When the MEK handed over its hundreds of tanks and artillery pieces to U.S. forces, the Bush administration agreed to protect the group and posted soldiers and a general at the camp for years. The army and the MEK even worked on joint patrols and other emergency plans.

But for Iraqi authorities the camp remained a no-go zone. In effect, the MEK attempted to defend a sovereign zone inside the post-Saddam Iraq, which U.S. officials say contributed to violence.

An Iraqi raid last year left 34 exiles dead.

The MEK has shown footage of the atrocities and gained U.S. support. But it said it needed the administration to act because the terrorist label helped Iraqi authorities justify mistreatment of its members and made it harder for residents to find permanent homes in other nations.

Most of its members are now in Camp Liberty, a former U.S. base designed as a compromise way-station for the United Nations to speed them out of Iraq peacefully. Several governments are weighing whether to accept them. Washington could allow the immigration of some, but none that were actively involved in terrorist attacks from the 1970s-1990s, officials have said.

After suffering a crackdown under Iran's monarchy, the MEK helped Ayatollah Ruhollah Khomeini overthrow U.S.-backed Shah Mohammed Reza Pahlavi in Iran's Islamic Revolution in 1979.

It then quickly fell out with Khomeini, and thousands of its followers were killed, imprisoned or forced into exile. It launched its campaign of assassinations and bombings against Iran's government in retaliation. The U.S. declared it a terrorist organization in 1997 at a time when Washington sought warmer relations with Tehran under the reformist presidency of Mohammad Khatami.

Yet the group also has provided the Americans with intelligence on Iran and convinced many governments that it has abandoned terrorism. In 2002, it revealed Iran's secret work on uranium enrichment near the city of Natanz -- intelligence that many speculated came from Israel's Mossad.

It claims to have a strong network of sympathizers and informants inside Iran. But would-be reformers have distanced themselves from the movement. The Green Movement that protested after the 2009 fraud-riddled re-election of President Mahmoud Ahmadinejad has publicly shunned the MEK.

Still, the group presses on with its goal of replacing the Iranian regime with a democratic, secular government. It says its parliament in exile includes Kurds, Baluchis, Armenians, Jews and Zoroastrians.

Because the MEK cannot operate legally in the U.S., it has lobbied its cause through several front organizations. Maryam Rajavi is the ostensible head of the whole movement from the France headquarters of the National Council of Resistance of Iran. Her husband, Massoud, was the MEK's leader before he disappeared in Baghdad nine years ago. He is presumed dead.

The terror designation "was illegitimate from the onset," said Shahin Gobadi, a Paris-based spokesman for the group. He called it an impediment to change in Iran, an unfair punishment of the MEK and the justification for Iraqi mistreatment of its members.