Court rules out referendum on Italy election law
Italy's top court has rejected a call for a referendum on the electoral law, which would seek to reverse changes enacted under Silvio Berlusconi.
It gave no immediate explanation for rejecting the petition, which had attracted more than double the signatures needed for a plebiscite.
Judges have 20 days to explain why they are not allowing the vote on a law which is deeply unpopular.
The law obliges voters to pick parties rather than individual candidates.
All parties apparently accept that the current law has to be changed but do not agree on how to do it.
Prime Minister Mario Monti, who heads a technocratic government and is expected to rule until the general election next spring, has said it is up to parliament, not his ministers, to make changes.
The constitutional court rejected both a proposal to dump the legislation, which is nicknamed the porcellum or "pigsty law", or to abolish only parts of it.
Supporters of abolition had collected 1.2 million signatures.
The law passed nearly seven years ago gives bonus seats in parliament to parties which win a relative majority in general elections.
Its creators said it was aimed at ensuring greater political stability in a country divided more or less equally between right and left.
However, in practice the law has resulted in significantly different majorities in the two houses of parliament, and has thus created greater political uncertainty and instability, the BBC's David Willey reports.
It is still uncertain whether a new electoral law will be passed by parliament in time for the next election, our correspondent says.