(see related story on Berlusconi) Rome, August 5 - There is no alternative to Premier Enrico Letta's executive, the head of Italian industrial employers confederation Confindustria said Monday. Letta's left-right grand coalition government is under threat after a tax-fraud conviction against ex-premier Silvio Berlusconi was upheld by the supreme court last week. There have been threats from Berlusconi's People of Freedom (PdL) party for its lawmakers and its ministers to quit en masse, which would bring down the executive cobbled together in April to end two months of deadlock after February's inconclusive general election. Three-time premier Berlusconi suggested Friday he would sink the government to spark early elections unless Letta's government quickly introduced reforms of the justice system, although on Sunday he vowed to continue supporting the administration at a rally outside his Rome home. Berlusconi says he is innocent of tax fraud and argues he is the victim of a campaign of persecution by leftwing elements in the judiciary that started when the billionaire media magnate embarked on a political career two decades ago. Letta, a member of the centre-left Democratic Party, said after Sunday's rally that he was pleased Berlusconi had renewed his support for the government, while stressing he was waiting to see whether his actions would match his words. Confindustria President Giorgio Squinzi, meanwhile, reiterated his view that Italy cannot afford a government crisis, as the country seeks to climb out of its longest recession in over 20 years. "The Letta executive is the only government that it was possible put in place after an anomalous election result," Squinzi told QN. "And there are no alternatives to this government. Whether you like it or not, we all have to support it because the real economy needs immediate responses". Squinzi said the priorities must be for the government to keep moving on payment of an estimated 90 million euros the public sector owes private forms and to reduce labour taxes.