Tensions have been rising steadily since the new prime minister announced legislation to grant himself immunity from prosecution, to suspend some trials and to jail journalists who publish wiretapped phone conversations.
With the weakened centre-left potentially unable to stop Berlusconi in parliament, the political climate has turned ugly - devolving into name-calling this weekend. La Stampa newspaper declared on its front-page: "It's Insult Time".
"I hope for a more calm and constructive climate," said Napolitano, who as president acts a neutral arbiter.
But opposition leader Walter Veltroni, who lost April elections to Berlusconi, said the time for dialogue with the billionaire media mogul was over.
Instead of fretting over Italy's faltering economy, where many analysts see growth of no more than 0.3 percent this year, Veltroni accused Berlusconi of working for his own interests.
"Italy is living its most dramatic crisis since after World War Two. Berlusconi is misleading the people and tends only to personal matters. That's it, dialogue is over," Veltroni told La Repubblica newspaper.
The 71-year-old premier, who faces a graft case in Milan, is opposing prosecutors who he believes are politically motivated and out to get him. He called them a "cancerous growth" last week.
"It is really a sign of the breakdown of the political system," said political analyst Franco Pavoncello at Rome's John Cabot University.
"The opposition is very weak. It is melting down ... so the government is pushing as hard as it can."
The centre-left's Antonio Di Pietro, a former antigraft magistrate, insulted Berlusconi using an offensive word over the weekend. Di Pietro took issue with wiretaps leaked to the media, which showed Berlusconi asking RAI's soap opera chief for TV roles for actress friends.
Last Mod: 30 Haziran 2008, 11:58