The transcripts form key evidence in an investigation led by prosecutors in Bari, southern Italy, against eight people suspected of providing Berlusconi with dozens of young women in 2008 and 2009 in order to win lucrative contracts, including with aerospace firm Finmeccanica.

The Italian press on Saturday published the juiciest exchanges. In one dated Jan. 1, 2009, Berlusconi, who will shortly celebrate his 75th birthday, tells how women were scrambling to spend the night with him.

The remarks were made to Gianpaolo Tarantini, a businessman who is the main person accused in the Bari inquiry.

Tarantini has been in custody since Sept. 1 accused of extorting 850,000 euros ($1.2 million) from Berlusconi to lie to prosecutors about the parties they were throwing.

These other proceedings are being led by a Naples court which last week requested to hear from Berlusconi as the “victim” in the alleged blackmail case.

In another conversation, the Italian prime minister talks with Marysthell Polanco, a young dancer from the Dominican Republic whose name has been featured in the “Rubygate” case, where Berlusconi is being tried for allegedly paying for sex with a minor.

He apologizes for not being able to spend much time with the performer, adding: “You know, Marysthell, in my spare time I’m the prime minister.”

Italy’s main opposition group the leftwing Democratic Party (PD) demanded his resignation Saturday.

“Italy, with the serious problems it is facing, cannot have an executive who governs in his spare time,” the party said.

“Berlusconi is in the hands of pimps and prostitutes who exploit him to get tender invites or senior positions in public businesses,” said Felice Belisario of the Italy of Values party, a partner of the PD.

One of Berlusconi’s ministers Saverio Romano backed the premier’s remarks, hitting out at “a lynching operation across the media” with its publication of “private conversations without a hint of criminality.”

On Monday Berlusconi will attend a trial hearing in Milan where is accused of paying former British lawyer David Mills 416,000 euros ($600,000) for false testimony about his business dealings.

Meanwhile, opposition leaders are demanding an inquiry to see if government aircraft flew a bevy of young women to Berlusconi’s private parties.

Leoluca Orlandi of the Italy of Values party is insisting that Berlusconi tell Italians if the planes were used after intercepted phone conversations in an investigation indicated they might have been.

Italy’s Sky TG24 TV on Saturday showed excerpts of transcripts in a probe of an Italian businessman who prosecutors allege paid women to have sex with Berlusconi at the parties.