ROME • Mr Matteo Renzi may be tendering his resignation as prime minister, but as leader of the biggest party in Parliament, he is the only one who can ensure a smooth transition to a new administration.

When President Sergio Mattarella begins the search for someone else to lead Italy's 64th government since World War II, perhaps as soon as next week, the backing of Mr Renzi's Democratic Party will be essential. The question is whether Mr Renzi, 41, will be able to deliver those votes.

Without Mr Renzi there to corral his lawmakers, chances of early elections begin to mount, potentially opening the door to the anti-euro Five Star Movement, run by Mr Beppe Grillo, 68.

A survey by EMG released on Sunday showed Five Star running neck and neck with Mr Renzi's party for first-round votes in a general election and winning with 53 per cent of the vote in the run-off, guaranteeing a majority.

While Five Star is demanding immediate elections, most other parties agree that the polls need to be put off at least until voting rules are changed to reduce the populists' chances. Mr Grillo is hostile to Europe and the euro, and his movement's victory would throw Europe into an economic and potentially political crisis.

Mr Grillo has for years advocated a referendum on Italy's euro zone membership status. Such a referendum would destabilise Italy's fragile economy and, particularly, the country's banks.

But there is no guarantee that Five Star would win such a vote, since recent polls show only 15 per cent of Italians support a euro exit.

BLOOMBERG, WASHINGTON POST