Rome: Promising to hang in as long as he is needed, Italian Premier Silvio Berlusconi on Sunday vowed not to quit and that could be a long time. He boasted playfully he'll live to 120.

"I'm not giving up. I'll be around as long as necessary," Berlusconi said, who has repeatedly proclaimed his innocence in all cases.

Berlusconi seemed to be thinking long-range. "I'll make it to 120 years, even though I'm still a mortal," Berlusconi joked.

Only a few days earlier, at a dinner for foreign correspondents, Berlusconi seemed to be telling the reporters that he has designated his justice minister as political heir, although he held out a role for himself as a kind of father-figure for his conservative Freedom People party.

Among the trials Berlusconi is involved is one in Milan in which he is charged with paying for sex with an underage prostitute.

74-year-old Berlusconi at the rally on Sunday kept up his railing against Milan magistrates describing them as "subversives" who sympathise with the left and are prosecuting him in hopes of ousting him from power.

Berlusconi had a pacemaker installed in 2006 after he collapsed during an appearance and has said he has beaten prostate cancer.

Three times premier, Berlusconi has also proven himself a political survivor since he entered politics two decades ago.

He has managed to hold on to a majority in Parliament despite the defection of a major center-right ally.