Ayatollah Ali Khamenei, Iran’s supreme leader, is coming under increasing pressure to rein in Mahmoud Ahmadi-Nejad, the president, over the radical stance he has taken on the country’s nuclear programme, analysts said on Tuesday.

The pressure is coming from Iran’s reformists and conservative pragmatists who have intensified their warnings about the threat they believe Mr Ahmadi-Nejad’s intransigence over the nuclear programme poses to national security.