Iran's supply of yellow cake uranium, which it acquired from South Africa in the 1970s, could run out within months, according to unnamed diplomatic sources quoted by the newspaper.

Diplomats from countries including Britain, the United States, France and Germany are lobbying governments in major uranium producing countries like Kazakhstan, Uzbekistan and Brazil not to sell Iran any more, the Times said.

While such efforts are unlikely to stop Iran from developing nuclear weapons, it could blunt its ambitions and help contain the threat, the paper reported.

Iran says its nuclear programme is for civilian purposes but many Western powers fear it wants to develop nuclear weapons and alter the balance of power in the Middle East.