Renzi’s book *Il Mostro*: the Constitutional Court is to rule on immunity from prosecution for defamation

It will be the Constitutional Court that decides whether the statements contained in the book ‘Il Mostro’, written by Senator Matteo Renzi, are protected parliamentary immunity. By Order No. 178 of 29 October 2026, adopted in chambers on 5 October, the Constitutional Court deemed admissible the appeal concerning the conflict of jurisdiction that arose between the Court of Milan and the Senate, after the Senate, on 25 July, had ruled that the statements made by Senator Renzi in the updated edition of the book were beyond challenge – pursuant to Article 68, first paragraph, of the Constitution – a guarantee that shields parliamentarians from legal action. These statements, and their publication by Mondadori Spa, are, however, the subject of a claim for damages brought by a public prosecutor in Florence who had investigated the parents of the former Prime Minister.

The affair began in 2023 with the publication of Renzi’s book *Il mostro. Inchieste, scandali e dossier. How they try to destroy your image’, the contents of which are deemed defamatory by the public prosecutor in charge of investigating two cases. The first case involved the senator’s parents, Tiziano Renzi and Laura Bovoli, on charges of alleged complicity in issuing invoices for non-existent transactions. The second case, also against Renzi senior, for the unlawful trading of influence. In the first case, the acquittal of the Renzis became final in 2023 following the ruling by the Court of Cassation. As for the second case, however, the matter came to a halt at the conclusion of the preliminary investigations with the order to dismiss the case issued by the Florence investigating magistrate in 2021.

The Constitutional Court clarifies that, in the appeal lodged by the Court of Milan, the statements made by Senator Renzi – which the Public Prosecutor considers defamatory but which the Senate regards as opinions expressed in the exercise of his parliamentary functions – are set out in full. This ruling prevents the Court – as the Milan judges explain – ‘from exercising its judicial function with any outcome other than a declaration of exemption from liability on the grounds that the Senator’s statements are beyond challenge or from the raising of a conflict of jurisdiction’.

According to the Milan Court, in fact, immunity would not apply in the absence of a ‘functional link between the statements made extra moenia and the exercise of parliamentary functions’. Not only that: it added that Senator Matteo Renzi’s statements would not correspond to any of the various opinions ‘made by him intra moenia and referred to in the Committee’s proposal approved by the contested resolution’; that the absence of a functional link would constitute ‘that disproportion between the guarantee for freedom of opinion enjoyed by a Member of Parliament in the performance of their duties and the right of third parties to bring proceedings before the courts, which has formed the basis of several judgments of the European Court of Human Rights’ (referring to the judgments of 24 February 2009, CGIL and Cofferati v. Italia; 20 April 2006, Patrono, Cascini and Stefanelli v. Italia; 3 June 2004, De Jorio v. Italia);

The Senate’s resolution would have resulted in ‘an unlawful interference by Parliament in the powers of the judiciary’, thereby necessitating the initiation of proceedings concerning a conflict of powers between the branches of government.