Eighty-one-year-old Mancino said he would prove his innocence "and my loyalty to the state".
Others send to trial over the mafia talks include former prime minister Silvio Berlusconi's ally, conservative senator Marcello Dell'Utri and another former minister and current MP, Calogero Mannino.
Prosecutors also asked for the indictment of three former paramilitary Carabinieri police officers and five top mafia bosses including Bernardo Provenzano and "boss of bosses" Salvatore 'Toto' Riina, who are both serving life sentences.
Two leading anti-Mafia prosecutors, Giovanni Falcone and Paolo Borsellino were both murdered by mafia bombs in 1992 and 22 people were killed in blasts at national monuments in Florence and Rome.
Mancino appears to have discussed with a senior official the possibility of getting Italy's chief anti-mafia prosecutor to intervene in his case according to extracts from a transcript of a phone-call he made to Italy's president Giorgio Napolitano leaked to the media earlier in July.
In a separate probe, Dell'Utri is being investigated by Palermo prosecutors for allegedly blackmailing Berlusconi.
He set to have a retrial after receiving a seven-year jail sentence for abetting the mafia. Italy's top appeals court in March ordered the retrial, saying Dell'Utri had not received a fair trial.
But in its explanation of the decision to order a retrial, the Court of Cassation said there was evidence that Dell'Utri had acted as intermediary with the mafia for Berlusconi, handing it "substantial sums" of so-called protection money.
Dell'Utri co-founded with Berlusconi the Forza Italia party in 1993, which later merged with the far-right National Alliance to become the People of Freedom.
The son of late mafia member and mayor of Palermo, Vito Cianciamino, Massimo Ciancimino, in 2010 testified in open court that Forza Italia resulted from a deal with the Sicilian mafia.