and the passage of laws under urgency. Once the bill has been approved in the same form by both houses of Parliament, it is sent to the President of the Republic, who must promulgate it within one month or send it back to Parliament for renewed debate with a written justification. If after the renewed debate the bill is approved by Parliament again, the President of the Republic is constitutionally required to promulgate it. Once it has been promulgated, the law is published in the official gazette by the Ministry of Justice and enters into force after the vacatio legis (15 days unless otherwise specified). Amendments to the Constitution and to constitutional laws The rigidity of the Constitution is ensured by the special procedure required to amend it. With the same procedure, Parliament can adopt a constitutional law, which is a law with the same strength as the Constitution. This process is referred to as iter legis aggravato, that is, a strengthened legislative process ad hoc for the passing of a constitutional law. Article 138 of the Constitution provides for the special procedure through which the Parliament can adopt constitutional laws (including laws to amend the Constitution), which is a variation of the ordinary legislative procedure. The ordinary procedure to adopt a law in Italy requires both Houses of Parliament to approve the bill in the same text, with a simple majority (i.e., the majority of votes cast). Constitutional laws start by following the same procedure; however, after having been approved for the first time, they need to be voted for by both Houses a second time, which can happen no sooner than three months after the first. In this second reading, no new amendments to the bill may be proposed: the bill must be either approved or rejected in its entirety. The constitutional law needs to be approved by at least a majority of all MP's in each house (absolute majority) in its second reading. Depending on the results of this second vote, the constitutional law may then follow two different paths. If the bill is approved by a qualified majority of two-thirds of members in each house, it can be immediately promulgated by the President of the Republic and becomes law. If the bill is approved by a majority of members in each house, but not enough to reach the qualified majority of two-thirds, it does not immediately