ROME (Reuters) - Italy's Constitutional Court on Thursday rejected a request by the hard-right League party to hold a referendum to introduce a first-past-the-post electoral system, triggering the ire of League chief Matteo Salvini and relief in government ranks.
The opposition League is by far Italy's most popular party, polls show, and its support is heavily concentrated in northern regions.
A first-past-the-post system would have raised the chances of a League-led centre-right bloc winning a big majority at the next election, piling pressure on the struggling government of the 5-Star Movement and the Democratic Party (PD).
The referendum proposed to change the electoral law simply by abolishing the proportional representation (PR) part of the current mixed system, but the court called this an "excessively manipulative" attempt at introducing a new system.
"It is a disgrace, it is the old system that defends itself ... We are sorry that the people are not allowed to decide: this is the return to pre-history of the worst Italian politics," Salvini wrote on Twitter.
The coalition of the anti-establishment 5-Star Movement and the centre-left PD is currently negotiating to introduce a purely proportional law which would limit the right-wing coalition's chances of a clear election win.
The next election is not due until 2023 but with the four-month-old government bickering over policies from the economy to justice reform and migrant rights, there is constant speculation that it could collapse much earlier.
The PD and the 5-Star have already agreed on a first draft of a purely PR electoral system that would set a minimum threshold of 5% of votes needed for each party to obtain seats in parliament.
5-Star leader and Foreign Minister Luigi Di Maio applauded the Court's verdict.
"Let's go ahead with the proportional law project so that all Italian citizens are actually represented in parliament," he said in a statement.
(Reporting by Angelo Amante; Editing by Gavin Jones and Giles Elgood)