A senior Iranian cleric yesterday called for protesters to be executed as "enemies of Allah", as authorities came one step closer to formally declaring Mahmoud Ahmadinejad winner of the disputed election.

The demand that demonstrators "must be shown no mercy" came as the main opposition leader Mirhossein Mousavi took a more conciliatory attitude towards authorities by saying he will seek official approval for future demonstrations – a significantly more emollient stance than 24 hours earlier, when he vowed to "neutralise this evil conspiracy" against the public. In addition his website was attacked by hackers, and is now blank.

The latest moves may signal the beginning of the end for the protests, which have swept Iran since the incumbent President Ahmadinejad claimed a landslide victory. The number of people attending marches has dwindled after demonstrators repeatedly came under attack from police and the Islamist Basiji militia, and almost 1,000 people were arrested.

Iran's Guardian Council yesterday seemed close to endorsing President Ahmadinejad as victor, in what it maintained was "one of the cleanest elections we have had".

Spokesman Abbasali Kadkhodai said allegations of fraud by the opposition had proved groundless. "After 10 days of examination we did not see any major irregularities," he said. "I can say with certainty that there was no fraud in the election." In his latest message Mr Mousavi urged supporters not to break the law, while maintaining that the struggle to have the polls annulled must continue. The opposition leader said he had been asked by the Interior Ministry to apply in person for rallies to be authorised, and to give a week's notice. He pointed out that while restrictions were imposed on his protests, supporters of President Ahmadinejad were able to hold marches "that were well publicised on state television, seeming to encourage participation, with their regularly advertised march routes."

The attitude of the hardliners meanwhile appears uncompromising. In a sermon at Tehran University, a venue believed to have been chosen deliberately because of the prominent role played by students in the protests, one Assembly of Experts member, Ahmad Khatami, said: "I want the judiciary to punish rioters without mercy, to teach everyone a lesson."

Mr Khatami's speech, which was broadcast nationwide, continued: "Based on Islamic law, whoever confronts the Islamic state should be convicted as mohareb [one who wages war against God] and punished ruthlessly and savagely. Under Islamic law punishment for those convicted as mohareb is execution."

He also claimed that Neda Agha Soltan, the icon of the opposition shot dead last Saturday, was killed by demonstrators. But Associated Press reported that a Basij militiaman shouted "I didn't want to kill her" after she died. Demonstrators stripped him of his identity card and took his photograph before letting him go.

The US, which has taken a harder line towards the regime in the past few days, has accused President Ahmadinejad of trying to deflect attention from popular discontent at home by blaming outsiders. White House spokesman Robert Gibbs said: "President Ahmadinejad is among people in Iran who want to make this not a debate among Iranians in Iran but about the West and the United States."

Russia, which along with China, had maintained that the election result should be accepted, said it was nevertheless, worried by the scale of violence by authorities. Foreign Minister Sergei Lavrov said: "We count on all questions which have arisen in the context of the elections being resolved in accordance with democratic procedures."

^Independent