"Iran's hardline spiritual leaders have issued an unprecedented new fatwa, or holy order, sanctioning the use of atomic weapons against its enemies," reports the Telegraph.

In yet another sign of Teheran's stiffening resolve on the nuclear issue, influential Muslim clerics have for the first time questioned the theocracy's traditional stance that Sharia law forbade the use of nuclear weapons.

One senior mullah has now said it is "only natural" to have nuclear bombs as a "countermeasure" against other nuclear powers, thought to be a reference to America and Israel.

The pronouncement is particularly worrying because it has come from Mohsen Gharavian, a disciple of the ultra-conservative Ayatollah Mohammad Taghi Mesbah-Yazdi, who is widely regarded as the cleric closest to Iran's new president, Mahmoud Ahmadinejad.