The outgoing leader of Italy’s political opposition apologised on Wednesday for being a failure, a day after Silvio Berlusconi, the country’s tycoon prime minister, won another election victory to concentrate even more power in his hands.

Walter Veltroni, a former mayor of Rome who was seen as the great hope of the centre left to defeat Mr Berlusconi, or at least tame him, stepped down as head of the Democratic party after it was routed by the prime minister’s governing party in a local election in Sardinia.