Syria’s most prominent defector has put himself forward as someone to unite the fractured opposition as the disparate factions were set to gather in Qatar today to try to agree on a transitional leadership if Bashar Assad’s regime is toppled.

The Syrian ambassador to Iraq has defected and will seek asylum in Turkey, the most senior diplomat to abandon the regime since the uprising against president Bashar Assad began 16 months ago, a Syrian opposition figure said today.

UN special envoy Kofi Annan has acknowledged that the international community's efforts to find a political solution to the escalating violence in Syria have failed.

US Secretary of State Hillary Clinton pleaded once more for global sanctions against the Syrian regime as president Bashar Assad was rocked by the defection of a top aide.