(By Paul Virgo) (see related story on Berlusconi) Rome, July 18 - President Giorgio Napolitano on Thursday warned that there would be "irreparable damage" if Premier Enrico Letta's left-right government were to collapse. Letta's executive, based on an unnatural and unprecedented alliance between the centre-left Democratic Party and ex-premier Silvio Berlusconi's centre-right People of Freedom (PdL) party, is under threat on many fronts. It is currently caught up in turmoil over calls for Deputy Premier and Interior Minister Angelino Alfano to resign over a scandal about the deportation of the wife and six-year-old daughter of a Kazakh dissident. The administration is also trying to resolve tensions over demands from the PdL that it avert a 1% rise of the top band of value added tax (VAT) scheduled for later this year and scrap an unpopular property tax called IMU. The PdL has said these are deal-breaker issues but the government is struggling to find money needed in the budget, with cash tight as Italy endures its longest recession in over 20 years and Rome committed to respecting EU fiscal-consolidation targets. The PdL may also sink the government if the supreme Court of Cassation next week upholds a four-year jail sentence for Berlusconi for fraud at his media empire that comes with a five-year ban from public office. But Napolitano, who was instrumental in the formation of Letta's government in April to end two months of deadlock following February's inconclusive general election, said more political instability was the last thing Italy needs. "If the continuity of this government is jeopardized, we will feel the repercussions in international relations and financial markets," Napolitano said. The head of State added that "pulling the plug" on the government would leave the country "in a void". There was some good news for Letta's executive on Thursday though when the PD, the premier's party and the biggest group in parliament, said it would back Alfano in Friday's no-confidence vote in the Senate over the deportation case. Letta has backed Alfano, saying the interior minister knew nothing of the expulsion until after it had taken place. Some PD lawmakers considered close to Florence Mayor Matteo Renzi wanted the party to join opposition groups in voting against the minister, despite the likelihood that this would have led to the PdL pulling its support from Letta's executive. Renzi is the PD's young, rising star. He is considering running to lead it later this year and has made no secret of his ambition to be premier one day. Some have accused him of making mischief for the government, which is unpopular with elements in the PD unhappy about the party being allied with its long-standing foes in the PdL. But in the end only a handful of PD parliamentarians voted not to back Alfano at a party meeting Thursday. ''In the PD group, there was a serious discussion...the group was virtually unanimous (in supporting Alfano),'' said PD Secretary Guglielmo Epifani. Alma Shalabayeva, wife of oligarch dissident Mukhtar Ablyazov Ablyazov, and their daughter were apprehended in a nighttime raid by Italian police at the end of May. They were rushed onto a private jet with Kazakh diplomats and flown back to a country whose human rights record has been questioned by several organisations. Alfano's chief of staff at the interior ministry resigned over the scandal earlier this week. The government has revoked the deportation order and Alfano has ordered a revamp of the departments involved in the expulsion. Economy Minister Fabrizio Saccomanni, meanwhile, said Thursday the government was making progress on the thorny issues of IMU and VAT, saying "a new method of enhancing relations" had developed within it.