From charismatic tycoon to lonely old man. Whatever the legal outcome of Italian prosecutors' inquiry into whether Silvio Berlusconi paid for sex with an under-age prostitute, the damage to his electoral appeal is devastating.

It will not come from Berlusconi's well-known penchant for young girls, but from the pitiful picture of a sad and gullible old man that emerges from the prosecutors' evidence and phone tapped conversations plastered over Italian newspapers for days.

The cultivated public persona of can-do dynamism, charm and even sexual charisma has been wrecked by the derisory comments of young showgirls discussing how ugly the prime minister is getting and how they can trick him into stumping up more cash.

"He's fatter than before, more dead than alive, he just has to cough up," transcripts of phone taps show one woman telling her twin ahead of one of Berlusconi's parties that both sisters are used to attending.

Berlusconi, 74, has laughed off calls for his resignation as madness. "I'm absolutely calm," he said. "I'm enjoying myself."

Indeed, the conservative leader has been written off many times since first becoming prime minister in 1994; but there is a growing sense that the latest scandal will be fatal to a man who has always been the epitome of the "image" politician.

"Berlusconi has become a figure of fun," said media and communications expert Klaus Davi. "He comes across as an old fool at the mercy of these girls and their relatives who use him as a sort of cash machine."

Hostile newspapers carry headlines such as "The end of the line" in Repubblica or "The tragedy of a ridiculous man", in Il Fatto Quotidiano. But greater harm may lie in the dismissive and pitying tone of editorials in several more neutral dailies.

La Stampa and Corriere della Sera both portray him as being easily duped by close aides and friends, and an article in Corriere della Sera likens him to an ATM machine used by cynical "friends" as well starlets in return for sexual favours.

Berlusconi's announcement he has a steady girlfriend has been universally ridiculed, with media speculating over which female politician or showgirl will volunteer for the role and dismissing the idea it could actually be true.

Milan magistrates allege that a "significant" number of young women prostituted themselves with Berlusconi at his homes, some dressing as nurses or policewomen to titillate him. Many allegedly lived in Milan apartments that he paid for.