Rome ? Prime Minister Silvio Berlusconi vowed to stay on and “go forward” Wednesday after an Italian court struck down a law granting him immunity from prosecution and allowed trials for corruption and tax fraud to resume in Milan. There were immediate calls for his resignation.

The decision by the Constitutional Court dealt Berlusconi one of the most serious blows in his 15-year-long battle with the Italian judiciary. It handed prosecutors another chance to ask for his conviction and added to a list of problems that already includes a headline-grabbing sex scandal.

The billionaire businessman-turned-politician dismissed any suggestion of resignation, and his conservative allies, who dominate parliament, quickly rallied to his support.

“Nothing will happen, we will go forward,” the premier told reporters in front of his residence in Rome.