Former Premier Silvio Berlusconi, who was hospitalized for tests after he fainted during a rally, will stay in the hospital for a couple more days, doctors and friends said Monday.

Emilio Fede, a news executive at one of Berlusconi's private TV networks and a close friend, said after visiting him at San Raffaele hospital that the conservative opposition leader would remain at least through Tuesday.

Berlusconi, 70, had said before checking into the hospital Sunday evening that he would be staying for 24 hours.

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Dr. Alberto Zangrillo, a heart specialist at San Raffaele, said Berlusconi would stay "a couple of days, no longer" while heart tests are done.

"For a person who had a fainting episode yesterday, which unfortunately all could see, keeping him in the hospital is correct from the medical point of view," Zangrillo said.

"He's a man who doesn't have time, so we are taking advantage of the occasion [of the hospitalization] for a proper cardiac examination," Zangrillo said.

Berlusconi's spokesman, Paolo Bonaiuti, said he would keep his commitment to lead a rally Saturday in Rome to protest the policies of Premier Romano Prodi's center-left government.

The hospitalization forced Berlusconi's ongoing trial in Milan to be adjourned to Friday, his lawyer Niccolo Ghedini said.

Berlusconi and British lawyer David Mills are on trial for false accounting, embezzlement and tax fraud in the purchase by Berlusconi's Mediaset empire of TV rights for U.S. movies. Both men deny wrongdoing.

The collapse also fueled speculation about Berlusconi's political future at a time when his leadership in the conservative opposition is being challenged.

"He doesn't want to, he must not and he couldn't quit," Bonaiuti told state radio.

Berlusconi nearly collapsed during a speech to supporters in the Tuscan spa resort of Montecatini Terme. His voice trailed off, and he gripped the podium for support as he leaned back. His aides rushed to keep him from falling over.

Bonaiuti said that Berlusconi had suffered a "very sharp drop in blood pressure" during the speech.

Berlusconi's personal doctor, Umberto Scapagnini, who was the first to come to his aid during the speech, was quoted as telling Milan daily Corriere della Sera daily that the former leader had suffered a "very brief loss of consciousness."

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