The Iranian Supreme Leader’s representative in Britain has told Muslim servicemen and women to quit the Armed Forces, saying that their involvement in the Afghanistan and Iraq wars is forbidden by Islam.

The cleric, personally appointed by Iran’s Supreme Leader, Ayatollah Ali Khamenei, to be his special envoy to the UK, also urged Muslims to defeat the opposition to the Iranian regime and keep the 30-year-old Islamic Republic alive.

In his first interview with an English language newspaper, Ayatollah Abdolhossein Moezi, director of the Islamic Centre of England, said he regretted that protesters were killed by the Iranian security forces after the presidential election in June but that their deaths were “unavoidable”.

Ayatollah Moezi, the most senior Iranian spiritual leader in Britain with thousands of followers from the Shia sect, said that it was wrong for followers of Islam to serve in the Armed Forces, especially in Afghanistan and Iraq where Muslims were being killed.

“Not only do I not accept it for Muslims to go there, I don’t accept non-Muslims to go there as well,” Ayatollah Moezi told The Times through an interpreter provided by him. “We say that Muslims are not allowed to go and kill Muslims. Do you think that Christians are allowed to go and kill Muslims?”

The cleric, 65, condemned the massacre in Texas last week of 13 American soldiers at the Fort Hood base by a Muslim military psychiatrist and insisted that it should not be used to tarnish the image of the world’s 1.5 billion Muslim population.

He said the September 11 attacks and the London bombings were wrong but accused the forces of “Zionist imperialism” of using the atrocities to smear Islam and its followers.

Ayatollah Moezi, 65, added that he advocated freedom of speech. He was confident that the opposition to President Ahmadinejad’s Government, led by the failed presidential candidate Hossein Mousavi’s Green Movement, would not topple the Islamic Republic.

“I believe the Islamic revolution has been absorbed to the deepest parts of our society,” said Ayatollah Moezi, who has been in Britain since 2004 after serving as the Supreme Leader’s special envoy to Vienna for four years.

“Of course, in our community we have people who do not accept Islam as a social entity and do not accept the revolution certainly. But these are not the majority in our society in Iran. And I believe that if those people in Iran who have a commitment to Islam, if they fulfil their duty towards Islam, the revolution will go ahead.”

During the interview at the Islamic Centre of England’s headquarters in Maida Vale, West London, the Ayatollah expressed his unease with some of the questions put to him, including those about the political situation in Iran. But he insisted that he would answer such questions to set the record straight and show that he was not afraid of being transparent and accountable.

Asked his views on the deaths of protesters in Iran — 36 according to the Iranian Government’s records and 72 according to the opposition — he said: “I believe that demonstrations everywhere in the world are free and should be free according to the law of the land. I am against killing and Ayatollah Khamenei is also against killing. However, in such clashes some sort of these incidents are unavoidable when you try to stop people from sabotage, from the acts that we have seen. Killings took place on both sides. But if anyone on purpose has killed someone else, they are liable.”

Ayatollah Moezi said he regretted the death of Neda Soltan, 26, a student, who the regime believes was killed by its enemies. The opposition maintains that she was killed by Iranian security forces.

He said her killers should be brought to justice. Ms Soltan, an Iranian student shot in the chest on June 20, has been held by Iran’s opposition movement and many in the West as a symbol of the regime’s brutality and suppression of human rights.

Ayatollah Moezi said Iran was entitled to pursue its nuclear ambitions for peaceful purposes. “The fact that Iran is entitled to use atomic energy has been admitted by the whole world.”

Ayatollah Moezi believes that Islam and politics are “inter-mixed” because religion “could not be ignorant of social issues. And part of social issues is politics, therefore Islam should have some sort of eye on political issues.”

He insisted that his role in Britain was to provide spiritual advice to all Muslims, irrespective of their sectarian backgrounds, and encourage them to become more involved in British society through education and employment.

He said the centre worked with police and other authorities to improve relations between the Muslim community and wider Britain.

“My personal belief is if Muslim migrants are better Muslims in this society, they can shape their individual lives in a better way and could be better members to this society,” he said.