Talks are underway in Berlin to discuss the next step in tackling Iran’s nuclear programme. Foreign ministers from Britain, Germany, China, Russia, France and the US are working on the follow-up to an ultimatum issued by the UN Security Council last night. The text, referred to as a “presidential statement”, called for Tehran to freeze uranium enrichment work within 30 days, or it would consider further action.Just what that further action would be is on the agenda today. One plan being circulated by the British would see the Security Council voting through a binding resolution that could impose economic sanctions on Iran if it refuses to suspend enrichment activities. That would prevent Iran arguing that the suspension of enrichment is technically on a voluntary basis.