Rome, September 12 - Premier Enrico Letta said Thursday he was sure a Senate panel vote next week on banning ex-premier Silvio Berlusconi would not sink the government. "I am serene, sure that good sense will prevail," said Letta, whose centre-left Democratic Party (PD) is allied with Berlusconi's centre-right People of Freedom (PdL) party in a shaky coalition. Letta said he would "work with determination" to prevent "Italy harming itself" by a government crisis he has said would cost the country more than a billion euros in higher borrowing costs. The PdL has said it will pull out of the coalition if the PD votes to strip Berlusconi of his Senate seat in accordance with his August 1 conviction for tax fraud at his media empire. The PD has said it will implement an anti-corruption law approved by both parties last year, which the PdL claims is being applied retroactively, and therefore against the Italian Constitution, in Berlusconi's case. The PD rejects the PdL's argument.