The eurozone has unlocked its $650bn crisis war chest, the European Stability Mechanism, amid worries over Greece and as Spain agonised over whether to call for a full bailout.

The launch of the 500-bn-euro ($650bn) ESM - immediately given an 'AAA' rating by credit giant Fitch - "marks an historic milestone in shaping the future of monetary union," Luxembourg Prime Minister and fund chairman Jean-Claude Juncker said.

Barnaby Phillips reports from London.