Silvio Berlusconi
Italy's Prime Silvio Berlusconi gestures during a family photo at an European Union leaders summit in Brussels February 4, 2011. REUTERS

Italian prosecutors will on Wednesday seek an immediate trial for Prime Minister Silvio Berlusconi, accused of paying for sex with an under-age girl and intervening improperly to have her released from police custody.

Once the request is submitted by Milan prosecutors, who believe they have enough evidence to skip a preliminary hearing and go straight to trial, the judge will have five days to decide, although the deadline could be extended by a few days.

We'll have a final meeting today on the procedural aspects and tomorrow we will forward the request to the judge, chief prosecutor Edmondo Bruti Liberati told reporters.

Milan prosecutors allege Berlusconi paid for sex with Karima El Mahroug, a Moroccan nightclub dancer known as Ruby, while she was under 18, the legal age for prostitution in Italy.

They say he later exerted improper pressure on police to have El Mahroug released when she was detained on separate theft allegations.

Prosecutors are likely to seek an immediate trial for both charges, judicial sources told Reuters on Tuesday.

Their request will add to the pressure on Berlusconi, who has been struggling politically since a split in his ruling PDL party last year and who faces a number of separate tax fraud and corruption charges.

He denies wrongdoing in any of the cases, saying he has never paid for sex and he accuses politically motivated leftist magistrates of trying to drive him out of power.

He has acknowledged making a phone call to police on El Mahroug's behalf, but says he was only helping a person in need.

LEGAL PROBLEMS

The 74-year-old premier, who has resisted calls to resign over the scandal, has faced mounting legal problems since the constitutional court last month struck down central parts of a law which gave him automatic immunity from trial.

Another trial in which he is accused of bribing British lawyer David Mills to give false testimony to protect his business interests is due to resume on March 11, judicial sources said.

The billionaire media mogul also faces charges of tax fraud and false accounting in a trial which is due to resume on February 28 and a separate hearing over a related case on March 5.

Berlusconi has so far refused to be questioned by Milan magistrates in the Ruby investigation, arguing they have no right to preside over the case, which he says he wants to be handled by impartial judges.

Leaked wiretaps from the probe have been splashed over the media, with references to bundles of cash, sex games and gifts that would-be starlets were alleged to have received after attending parties at Berlusconi's villa.

Lawyers for the prime minister have presented evidence to magistrates from dozens of witnesses denying accounts of wild erotic parties at his residence.

The scandal has prompted growing numbers of protests throughout the country, often organised spontaneously or via the Internet, although opinion polls show little sign of any damage to Berlusconi's among his conservative voter base.