PALERMO - A jailed Mafia boss told an Italian court on Friday he had never had ties with a close associate of Silvio Berlusconi, casting doubt on evidence from another mobster linking the prime minister to Cosa Nostra.

Sicilian clan boss Filippo Graviano, serving multiple life terms with his brother Giuseppe for their part in a 1993 Mafia bombing campaign, denied seeking help from politicians or having any contact with pro-Berlusconi senator Marcello Dell'Utri.

Asked whether he knew Dell'Utri, directly or indirectly, Graviano told the Palermo court via video link, his face obscured on television: No.

He also said he had neither sought political protection, nor to cooperate with magistrates, after his arrest in 1994.

There was no need to ask help from anyone, he said. There was no one who had something to promise me.

Berlusconi is not formally linked to the case being heard in Palermo, an appeal by Dell'Utri against his nine-year jail term for association with the Mafia, which has thrown up new evidence alleging links between Berlusconi and the mob.

Berlusconi says these allegations are unfounded and part of a campaign by biased courts to bring down the government, his third since he entered politics in 1994 after building up Italy's largest private broadcasting network, Mediaset.

He says his government has been the toughest in the fight against the Mafia and has dismissed court evidence by mobster-turned-witness Gaspare Spatuzza, who linked him and Dell'Utri to the Graviano clan, as a revenge by the mob.

Spatuzza said last week that Giuseppe Graviano had told him in January 1994, shortly before he was arrested, that the clan had obtained everything thanks to Berlusconi and Dell'Utri. Unlike his brother, Giuseppe Graviano refused to answer the prosecutor's questions on Friday.

What were you expecting? Berlusconi told reporters on Friday when asked to comment on Filippo Graviano's statement.

Dell'Utri, a Sicilian who helped Berlusconi found his Forza Italia party, said: I'm tired. Why don't they look for the real culprits instead of me?

Florence prosecutors who reopened the investigation into the 1993 Mafia bomb attacks in Florence, Rome and Milan -- in which 10 people were killed -- say Berlusconi is not being investigated.

The conservative leader, 73, has been on the warpath against the judiciary since Italy's Constitutional Court overturned a law granting him immunity from prosecution in October, allowing fraud and corruption trials against him to resume.

His scathing attacks on magistrates have put him at odds with one of his main allies, lower house speaker Gianfranco Fini, and with the head of state, President Giorgio Napolitano.

His image has also been hurt by a sex scandal and a messy divorce, although he still enjoys relatively high popularity ratings of around 45 percent.

On Friday, Berlusconi denied media reports that he was considering an early election, banking on a likely victory to silence critics and show that voters were still on his side.