According to an old Italian law from 1957, if you have a licence to perform public functions if you can’t be a MP.
Apparently this applies to Berlusconi, whose Mediaset Group has a licence to use TV frequencies, which in Italy are an exclusive propriety of the State. Yes, Berlusconi is only a shareholder in the Group, which is managed by his sons; but in Italy, it would be easy to argue that the Berlusconi family is one familiar enterprise.
Pursuant to Italian Constitution, the decision must be taken by an Electoral Jury of the Senate, composed of members of the main parties. The decision is not subject to judicial review.
The jurors of the Five Stars Movement will vote to throw Berlusconi out of the Parliament, and are making huge pressure on the Democratic Party to do the same. The Democratic Party simply can’t comply, since it is supporting the Letta Government together with Berlusconi. But to vote for the Cavaliere will be a huge embarrassment for the Italian left.