By Guy Dinmore in New York
September 15, 2005

The presence at the United Nations of Iran's new hardline president, Mahmoud Ahmadi-Nejad, has galvanised the exiled opposition into action.

Still, historical and ideological differences have prevented rival groups from presenting a united front.

Opposite the UN headquarters in Manhattan, several thousand Iranians, many of whom fled to the US during the 1979 Islamic revolution, have held noisy protests this week denouncing the Iranian president as a "terrorist".

Mr Ahmadi-Nejad, the former mayor of Tehran who is regarded as an Islamic fundamentalist close to the Revolutionary Guards, is alleged to have interrogated captive US diplomats while a student leader 25 years ago, and to have been implicated in the execution or assassination of opposition activists in Iran and abroad.

Iran has denied all such allegations, but Mr Ahmedi-Nejad's visit got off to a controversial start when the Bush administration, which is investigating the claims by the former embassy hostages, only reluctantly agreed to give him a visa because of its legal obligation as host country to the UN.

When the Iranian president made his debut on the world stage on Wednesday, delivering a fiery speech against US imperialism and western spiritual degradation, the US delegation led by Ambassador John Bolton made sure it was absent from the chamber.

One opposition group, the People's Mujahideen Organisation (known as the MKO), and its political front, the National Council of Resistance of Iran, has tried to capitalise on the obvious US hostility towards the newly-elected president and the Islamic republic's suspected nuclear weapons programme.

Both organisations are banned in the US as terrorist groups because of their alleged attacks on US citizens in the run-up to the 1979 revolution, and on Iranian civilians since then.

But the ban did not prevent many supporters from holding banners and wearing T-shirts bearing the image of Maryam and Massoud Rajavi, the husband and wife team who effectively lead the twin organisations and their Iraq-based military forces that were once supported by Saddam Hussein but are now sequestered by the US army.

Brian Binley, a conservative party member of the UK parliament, was among a handful of western politicians there to express his support for the MKO and efforts to take the organisation off the terrorist list in the UK.

"We should do all we can to ensure that the regime in Iran is defeated," he told the FT, explaining that this did not rule out the UK government's current policy of engagement.

Hedayat Mostowfi, who is still an activist but because of the ban describes himself as a former member of the Council, says the Clinton administration outlawed the groups in an attempt to "appease" the Iranian regime at a time when the US was trying to build bridges to Mohammad Khatami, the then reformist president.

"Ahmadi-Nejad is a result of all this appeasement," Mr Mostowfi commented, declaring that the Iranian people were ready to overthrow the regime themselves but that the US had to demonstrate first that it was ready to combat Islamic fundamentalism in Iran by lifting the ban on the MKO.

"The people of Iran will not get motivated unless you send them a clear message," he said. Behind him, a large screen projects a video of cohorts of young Iranian women who formerly made up a part of the MKO's armed forces, singing martial songs dressed strictly according to Islamic rules.

Nearby, a smaller group of several hundred supporters of Reza Pahlavi, the son of the last Shah of Iran, demonstrated their desire to re-establish the monarchy, though this time as a constitutional power alongside an elected government.

Mixed in were also secular student leaders who seek a republic. The rivalries between these groups illustrate the problems facing the Bush administration in its efforts to support and fund the disparate and largely ineffectual opposition in exile.

To some of the monarchists, the MKO is a cult-like organisation with left-wing Islamist tendencies that would be even worse than the current regime. A woman simply calling herself Azar from California denounced the MKO as "terrorists" and "traitors" for having sided with Saddam Hussein during the Iran-Iraq war from 1980 to 1988.

She said she was horrified that some MKO members had torched themselves last year in protest against the detention of Mrs Rajavi in France. The French authorities later released her. Azar calls herself an American Republican supporting the Bush administration, but an Iranian royalist wanting the restoration of the monarchy.

Nearby, Marokh, an MKO supporter, said she had spent six year's in Tehran's Evin prison. She held a picture of her brother who she said had been hanged by the regime. She and Ali, a man beside her, say they do not like the royalists, who "want the same king as before". They are hoping that Mr Bush will bring his troops home from Iraq via Iran.