Italy’s highest court has opened the way for early elections in 2017 after favouring a form of proportional representation in a ruling that could bolster former prime minister Matteo Renzi’s chances of making a comeback.



In a verdict on the legality of an electoral law brought in by Renzi’s government, the constitutional court also said a party winning at least 40% of the vote could be given an automatic parliamentary majority.



But it rejected the part of the so-called Italicum law, approved in 2015, that called for a runoff ballot in future national elections, saying the vote should be held in just one round. Critics feared a runoff round would leave too much power in the hands of one party.

The law had been a cornerstone of Renzi’s broader reform plan and one he hoped would end decades of political instability.



Matteo Renzi resigned after losing a referendum in December. Photograph: Alessandro Bianchi/Reuters

The court was forced to scrutinise its legality since the law had only applied to the Italian parliament’s lower house – the Senate had been marked for abolition in a separate set of reforms, but these were rejected in a referendum in December 2016 that led to Renzi’s resignation and replacement by Paolo Gentiloni.

The idea of proportional representation could hobble the populist Five Star Movement’s chances of winning an election, as the party refuses to form coalitions, but founder, the comedian Beppe Grillo, immediately renewed his call for an early election following the verdict, saying his party would aim to win 40% of the vote.



Renzi, leader of the centre-left Democratic party, is also keen for an early election in which he may perform better than the ballot scheduled for Spring 2018.

Analysts cautioned that while the court’s decision means the law could be applied immediately, a vote was unlikely until the electoral systems of both chambers were harmonised.



“From a legal point of view, the law is legitimate, but given the differences between the lower house and the upper house, having an election now will only bring instability,” said Franco Pavoncello, a political science professor and president of Rome’s John Cabot University. “Also there is a feeling that the Gentiloni government has given the country some stability and that now is not the time for another big shock.”

Beppe Grillo has called for early elections. Photograph: Marco Bertorello/AFP/Getty Images

Perhaps intentionally, Renzi, 42, marked his comeback campaign on Wednesday with the launch of a new blog in which he talked of the importance of “moving forward”.

He said the referendum defeat hurt, but stressed that the blog was a way to “walk towards the future”.

Francesco Giavazzi, an economics professor at Milan’s Bocconi University, said the ruling was unlikely to make much of a difference. “The consensus among political players is to have an election in spring 2018; there is no appetite for an early vote other than from Renzi,” he said.

Giavazzi added that if Renzi pushed for an election in June he could win, but not if it was held next year.

“Every day he’s out of power, people lose interest in him – it’s already happening, people are forgetting him. There’s also a risk, with the number of people against him within his party increasing, that he’ll also lose the leadership of the Democratic party,” he said.