The son of Iran's supreme leader, Ayatollah Ali Khamenei, has taken control of the militia being used to crush the protest movement, according to a senior Iranian source.

It is the ultimate slice of political Americana an unscripted no-holds-barred sparring contest between candidates pitting their wits, chutzpah and political virility before an audience of millions. Now the televised debate, a long-established hallmark of US presidential elections, could be given an airing in an unlikely setting: Iran, which for 30 years has denounced America as the "great satan" and spurned its cultural innovations