Ali Akbar Dareini, Tehran Iran's former senior nuclear negotiator, Hossein Mousavian, has been charged with passing classified information to foreigners, including to the British embassy, the Iranian Intelligence Minister said yesterday according to the official Irna news agency.

"He has been informed of the charges that he has given the British embassy information contrary to the security of the country," the news agency quoted Gholam Hossein Mohseni Ejehi as saying.

There was no word on when he would be put on trial.

Mousavian - who was the top nuclear negotiator under former reformist President Mohammad Khatami - was briefly detained in May on suspicion of espionage according to the Fars news agency.

"His crime from the viewpoint of the Intelligence Ministry is obvious and provable," Irna quoted Ejehi as saying.

On Monday, President Mahmoud Ahmadinejad blasted critics of his nuclear policies as "traitors" and accused them of spying for Iran's enemies, using his strongest rhetoric yet against domestic opponents and raising concerns of a possible crackdown.

"We even have a recorded speech of one of them telling the enemy, Why should you give up? Step up pressures to make them (Iran) retreat'," Ahmadinejad said, without identifying the person.

Ahmadinejad warned that his government would not let political groups use their "political and economic influence to save criminals from the clutches of justice".

Ejehi, himself a former top judge, named Mousavian directly in his comments yesterday, saying "influential persons have called the judge and sought to get him acquitted".

Mousavian appeared on Monday next to his ally, former president Hashemi Rafsanjani when he warned Iran was facing "serious threats". It was Mousavian's first major public appearance since being released in May.

When he came to power in 2005, Ahmadinejad removed the negotiating team, which he had accused of making too many concessions to the West. He installed his own team, led by Ali Larijani and has since taken a tough line, refusing to bend to UN demands to suspend its uranium programme.

Larijani, however, did build a good relationship with the UN and developed a style at odds with the President's more confrontational approach. He abruptly resigned in October.

Domestic criticism has lately mounted against the President over the nuclear issue, with Hasan Rowhani, another former top nuclear negotiator, delivering an unusually sharp rebuke to Ahmadinejad last month. AP