Presidents have a lot of ceremonial duties, but step in whenever there is a political crisis, a fairly frequent occurrence in Rome. They act as kingmakers to any new government, they oversee the judiciary and are party to sensitive intelligence and defence matters.

With Mr Berlusconi, Italy would gain a head of state with a criminal record, thanks to his 2013 conviction for tax fraud. He would also be a president on trial, as he is still facing criminal charges related to the infamous “bunga bunga” affair, which he denies.

The case saw the former premier indicted for soliciting sex from an underage prostitute known as “Ruby the Heart Stealer”. He was cleared on appeal, but he was put on trial again, before three separate courts, on suspicion he bribed defence witnesses.

One trial ended with an acquittal in October, two are still pending.

Nevertheless, his fans insist his bid for the presidency – which carries a seven-year mandate – is serious.

Presidents are elected in a secret ballot by around 1,000 national and regional lawmakers. Voting is due to start around January 20 and the outcome is likely to be unpredictable until the last minute, influenced by backroom deals.

“He has a 50-50 chance to make it,” Gianfranco Rotondi, a veteran Forza Italia MP who was a minister in Berlusconi’s last government, in 2008-2011, told the Telegraph.

Former premier and M5S leader Giuseppe Conte said this week: “I respect Forza Italia’s leader, but he is not our candidate.”