(ANSA) - Grosseto, December 16 - Italy's supreme Cassation Court will review on January 31 an appeal motion against a plea bargain awarded to five staff members in the shipwreck of the Costa Concordia cruise liner that killed 32 people early last year off the coast of Tuscany. Prosecutors in Florence are contesting a judge's lighter jail sentences given in July to crisis-management chief Roberto Ferrarini (two years, 10 months), hotel quarters director Manrico Giampedroni (two and a half years), first officer Ciro Ambrosio (one year, 11 months), officer Silvia Coronica (one year, six months) and helmsman Jacob Rusli Bin (one year, eight months), each accused of multiple manslaughter. Prosecutors argue the suspects did not earn their plea bargain, "having made no particular contribution to the investigations" with their "generic testimony". The former captain of the doomed ship, Francesco Schettino, is on trial for multiple manslaughter and dereliction of duty, and could face 20 years in prison if he is found guilty.