Prosecutors also asked that Lusi be banned from holding public office and ordered the confiscation of 25,479,200 euros seized from Lusi, who was the Daisy Party treasurer.
The prosecutors accuse Lusi, of criminal association aimed at misappropriating funds and of slandering politician Francesco Rutelli, a former mayor of Rome and leader of the Daisy Party.
Lusi "exercised virtually total dominion over the Daisy party's funds," said public prosecutor Stefano Pesci.
"Only he knew of individual operations and could sign for payments, apart from Rutelli, who never exercised his powers," Pesci added.
Prosecutors at Lusi's trial requested prison sentences of three years and of two years and two months for two of his tax advisors.
The former senator, went on trial last year and was arrested in June 2012.
Lusi's wife plea bargained a one-year suspended sentence, prosecutors said.
The Daisy Party, once Italy's largest left-leaning party, was founded in 2002 and in 2007 merged with a rival centre-left party to form the Democratic Party, currently the main party in the coalition government and Italy's most powerful political organisation.