A referendum, in the Italian legal system is a request directed to the whole electorate to express their view on a determined question. It is the main instrument of direct democracy in Italy. The Constitution of Italy only provides for four types of legally binding referendums: A popular referendum, in which the electorate is called to vote on whether they wish to abolish (abrogate) an existing law, either totally or partially. A constitutional referendum, which can be requested in some cases when a new constitutional law is approved by Parliament. Similarly, a referendum can be requested to confirm the adoption of the Statute of ordinary regions. An advisory referendum is required to approve the modification of regions, provinces, or municipalities. A popular referendum on regional laws and regulations may be regulated by regional statutes. Despite that the constitutional right to hold a popular referendum has existed since adoption of the Constitution in 1948, the necessary legislation detailing the bureaucratic procedures needed to hold them was not adopted until the early 1970s. As a consequence of this, Italy's first popular referendum was not held until 1974, 27 years after the constitution was first approved. Popular referendums Requirements A popular referendum can only be called only at the request of five Regional Councils or 500,000 Italian voters. A popular referendum can only be asked to abolish an existing law (or part of it); a referendum to adopt new legislation is not provided for by the Constitution. Some matters are not subject to popular referendum: tax laws, budget laws, amnesties and pardons, and laws that authorize the ratification of international treaties. While these are the limits expressly stated by the Constitution, the Constitutional Court has identified further limitations. The petition, which must include the question of the referendum, must be deposited at the Court of Cassation, which is called to examine the validity of the petition. The Constitutional Court of Italy verifies the regularity of signatures (in case the referendum was requested by the voters) and of the question of the referendum. The court has the power to reject it outright. Many fully valid petitions with the necessary 500,000 signatures have never been accepted as referendums precisely for this reason. If the Court of Cassation judges the petition to be valid, the referendum question must then be evaluated by the Constitutional Court, which is called to judge its admissibility. Unlike the Court of