There are many good reasons why Giorgio Napolitano, Italy’s head of state, has turned to Enrico Letta in his attempt to break the political deadlock in Rome. The deputy leader of the centre-left Democrats comes from the moderate, Catholic wing of his party. His reputation as a bridge-builder will be handy as he seeks to reach out to Silvio Berlusconi to put together a grand coalition government.

It is still possible that Mr Letta will not succeed in forming an executive. Anyway, his government is unlikely to last for long. The Democrats and the People of Liberty are bitterly divided. Silvio Berlusconi is an unreliable coalition partner, as he showed last December when he unexpectedly pulled the plug on Mario Monti’s technocratic government. The Democrats are split and face a momentous change of leadership after the resignation of their former chief, Pier Luigi Bersani.

If Mr Letta succeeds in his first task, he should be realistic about what his government can achieve. His first speech as prime minister designate talked about the need to change the EU’s mantra of universal austerity. While this message is sound, a weak Italian government stands little chance of getting Germany and other creditor countries to change tack.