(By Denis Greenan). Rome, September 16 - Silvio Berlusconi's People of Freedom (PdL) party claimed Monday a cocky election prediction by the leader-in-waiting of their uneasy coalition partners in the Democratic Party (PD) means the PD wants to vote the media magnate out of the Senate and hurry Italy to the polls. The PdL and PD have been tangled in a war of words - which some observers have called a phony war but others say poses an imminent threat to Premier Enrico Letta's unprecedented right-left government - ever since Berlusconi's first definitive conviction on August 1 in his 20-year struggle with a judiciary he claims is left-wing and biased. The four-year term - cut to one by an amnesty - mandates an automatic ban from office under an anti-corruption law voted in by the PD and PdL last year to help counter widespread public disgust at a slew of scandals. Despite its already being applied to over 20 local cases, the PdL now claims it is against the Italian Constitution because the tax fraud Berlusconi was found guilty of took place years before the conviction, thus making the ban allegedly retroactive. The PD has dismissed this argument and says it will vote to eject Berlusconi from the Senate in accordance with the law, first on a Senate panel set to recommend action this week and, later this month, in the full Senate vote requited to ratify the ban. The PdL says it will pull the plug on Letta if the PD votes to boot out its leader. It says that will be the PD's fault for having stuck to an allegedly hostile and over-literal interpretation of the law out of an unconquerable urge to put a judicial end to a rival they have rarely defeated politically. The PD, responds, in turn, that insists no one is above the law and the PdL must shoulder the responsibility for sparking a government crisis that Italians do not want. Florence Mayor Matteo Renzi, tipped as a shoo-in for the centre-left's party's leadership when it votes a new head later this year, said Sunday Berlusconi's party would "obviously" be to blame if Letta is toppled by the PdL withdrawing support to prove its loyalty to its charismatic boss. But if the country goes to the polls less than a year after February's inconclusive election, he said, the PD would "tarmac over" the PdL in a crushing win as voters penalise the PdL for its "irresponsibility". Various PdL heavyweights accused Renzi of being over-confident Monday, and claimed his "cocky" prediction meant the PD is spoiling for a fight and wants to go to the country despite the damage this would do to the economy and Italy's efforts to keep inside EU deficit targets despite an inevitable spike in borrowing costs that would come with a government crisis. "Renzi's words are the proof the PD wants elections," said former Senate Speaker Renato Schifani. He was backed by former minister Stefania Prestigiacomo, who said "the PD is showing its true colours", and one of Berlusconi's most vehement defenders, Daniela Santanché, who said Renzi "is getting too big for his boots, and he's the one who's going to end up tarmacked". Pier Ferdinando Casini, leader of a small ex-Christian Democrat centrist party that joined former technocrat premier Mario Monti's Civic Choice party, a junior partner in Letta's government, also accused Renzi of being too brash and provocative, saying he had increased the likelihood of a crisis. A snap vote, Casini said, would "tarmac over the country", killing a nascent recovery from Italy's longest postwar recession. Renzi was undaunted, quipping that, as Florence mayor, "we have tarmacked 132 kilometres of road so I would just be continuing the work". Amid the renewed tensions, Letta said he had received a bottle of holy water from the Catholic shrine at Lourdes as he continues what he has called a "huge effort" to keep the unruly coalition together. Beppe Grillo, leader of the anti-establishment 5-Star Movement (M5S) whose surprisingly big success in the February election and refusal to talk to the PD forced a two-month stalemate, has suggested some in the PD might even prefer the government's survival to sinking their archenemy in the secret of the Senate voting booth. He is calling for an open vote.