Italicum

The Italian Electoral law of 2015, officially Law 6 May 2015, no. 52, colloquially known by the nickname Italicum, given to it in 2014 by the Democratic Party secretary and subsequently head of government Matteo Renzi, who was its main proponent (until the end of January 2015 with the support of Forza Italia's leader Silvio Berlusconi) provides for a two-round system based on party-list proportional representation, corrected by a majority bonus and a 3% election threshold. Candidates run for election in 100 multi-member constituencies with open lists, except for a single candidate chosen by each party who is the first to be elected.

The law, which came into force on 1 July 2016, regulates the election of the Chamber of Deputies, replacing the previous electoral law of 2005, modified by the Constitutional Court in December 2013 after judging it partly unconstitutional.

The law was written under the assumption that, by the time it came into force, the upper house would have become an indirectly-elected body representing regions, with greatly reduced powers, thus making a reform of its electoral system unnecessary. The upper-house reform, rejected in the 4 December 2016 Constitutional Referendum, was originally assumed to be adopted without a Referendum by 1 July 2016. Despite the non-adoption of the reform as scheduled, had it been adopted in the referendum, it would have still been in force at the first elections held under the law, which are scheduled to be held on 23 May 2018.

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