(see related) Rome, August 22 - A minister from the center-left Democratic Party (PD) on Thursday slammed his center-right government coalition partners for "bargaining" with the stability of the cabinet over ex-premier Silvio Berlusconi's pending ban from office. "To all the threats and ultimatums, just answer with this simple principle: you cannot bargain to swap lawfulness and respect for the rules in exchange for government stability. Never," said Minister for Relations with Parliament Dario Franceschini. The Senate is set to vote September 9 on stripping three-time premier and media magnate Berlusconi of his place in the upper house according to a new anti-corruption law that kicked in after his August 1 conviction for tax fraud, his first definitive sentence in almost 20 years of battles with magistrates he accuses of left-wing bias. In the two-hour meeting late Wednesday, Deputy Premier and PdL No.2 Angelino Alfano told Premier Enrico Letta that his party could not contemplate staying in the cabinet if the centre left votes Berlusconi out of the Senate.