Italian Premier Romano Prodi, already embroiled in a row over Telecom Italia, faced another threat on Tuesday from a rebel senator in his own centre-left coalition .
Senator Sergio De Gregorio called a press conference at a Rome hotel to announce his defection from a government party called Italy of Values (IDV) and the creation of a new movement called Italians in the World .
De Gregorio, who heads the Senate Defence Committee, said his movement already had the support of at least three senators and four members of the House .
The desertion was bad news for Prodi, who hangs by a thread in the Senate after winning the narrowest of victories against former premier Silvio Berlusconi in the election .
Prodi emerged from the April vote with a solid majority in the House but only two more seats than opposition chief Berlusconi in the Senate .
The upset to the precarious 158-to-156 seat balance worsened with the possibility that other senators on the centre left had joined De Gregorio or were about to .
This would leave the premier increasingly reliant on the chamber's seven life senators, most of whom are sympathetic to the government, together with another independent senator voted by Italians resident abroad .
De Gregorio was flanked at the press conference by Federica Rossi Gasparrini, the long-time leader of the Italian housewives' movement who was elected to the House with the IDV .
Gasparrini was the only supporter of De Gregorio's new party to go public but the senator said the others were waiting in the wings and would come forward "very soon" .
Berlusconi, a billionaire media magnate, said earlier this month that some 20 centre-left senators were ready to quit the governing coalition, a move which would effectively torpedo Prodi's government .
But De Gregorio remained ambiguous, saying that his movement had no intention of joining the opposition or toppling the four-month-old government but would instead chart a grey area between the two poles .
"I won't be the one to bring down Prodi... And we certainly won't be delivering ourselves over to the opposition," said the 45-year-old Neapolitan journalist and businessman whose political past includes a stint with Berlusconi's Forza Italia party .
"Our aim is to develop dialogue between the two sides. Choosing one or the other would end the process of developing this political area," he said .
"We want self-determination for lawmakers who are tired of following party lines they no longer agree with. We want to create a broad alliance which will break this bipolar system in which two coalitions battle each other in a sterile war," he said. The senator nonetheless raised a pistol to the government's head, stressing that he would refuse to back Prodi in any more confidence votes which sidelined the opposition or excluded debate with the centre right .
Parliamentary weakness coupled with internal policy divergences in his disparate nine-party coalition have forced the premier to resort to at least nine confidence votes since coming to power, seven of them in the Senate .
De Gregorio also fired a warning shot at Justice Minister Clemente Mastella, who heads the centrist UDEUR party, telling him that he would vote against his justice reform bill. The senator's move comes at a difficult moment for Prodi, who has been accused of interfering with company strategy at Telecom Italia, Italy's biggest telecommunications group .
Prodi will be grilled on the Telecom affair in the House on September 28 .
The ruckus has already cost him his close advisor Angelo Rovati, who resigned on Monday, while Telecom's controlling shareholder Marco Tronchetti Provera abruptly quit as the group's chairman last Friday citing tensions with the government .
