Berlusconi has repeatedly questioned the legitimacy of the legal degree of the former Operation "Clean Hands" magistrate and leader of the Italy of Values party, Antonio Di Pietro, when he during a 2008 election rally and in an episode of the talk show Porta a Porta in March 2008 he repeatedly claimed that Di Pietro had not obtained his degree by passing the exams, but with the aid of the secret services, in order to have a judge placed in the system to overturn the parties of the so-called First Republic. Di Pietro subsequently sued Berlusconi for aggravated defamation in June 2008. The public prosecutor concluded the preliminary investigation 13 November 2009, by indicting Berlusconi for the defamation offence referred to in Article 595 paragraph 2 of the Criminal Code. The Italian Chamber of Deputies then intervened in the case by passing a decree 22 September 2010, granting all Italian parliamentarians "absolute immunity" for words spoken while elected.