ANKARA - Turkey's parliament has passed a bill to close down thousands of private schools, many of which are run by an influential Muslim cleric embroiled in a bitter feud with the government.The move is the latest blow struck in a rivalry between Prime Minister Recep Tayyip Erdogan and his former ally Fethullah Gulen which has seen the Turkish government entangled in a graft scandal and shaken to its core. In a late-night session on Friday, lawmakers in the 550-seat house voted 226 for and 22 against the bill which sets September 1, 2015 as the deadline to shut down the network of schools.Around 4,000 private schools in Turkey are run by Gulen, and provide a major source of income for his Hizmet (Service) movement, which describes itself as a global, social and cultural movement inspired by Islamic ideals.Tensions have long simmered between Erdogan and Gulen, who once worked hand-in-hand as the conservative pro-business middle class rose at the expense of the military and former secular elite.But they reached breaking point in November when government first floated the idea of shutting down the schools, which aim to help students prepare for high school and university.Erdogan said at the time he wanted to abolish an "illegal" and unfair education system which he charged turned children into "competition horses"."Those who benefit from these courses are the kids of rich families in big cities," said the Turkish premier, who himself hails from humble roots and has tried to burnish an image as a man of the people during his term in office.Corruption crisis In mid-December dozens of Erdogan's allies were detained in police raids on allegations of bribery in construction projects, gold smuggling and illicit dealings with Iran.Erdogan accused so-called Gulenists implanted in Turkey's police and judiciary of instigating the corruption probe in a bid to undermine his government ahead of local elections in March and presidential elections in August. He retaliated by sacking hundreds of police and prosecutors believed to be linked to the movement run by Gulen, who lives in self-imposed exile in the United States.A Turkish court on Friday released the last five suspects detained in the corruption probe, including the sons of two former ministers. However the corruption crisis, which dragged down four ministers and prompted a cabinet shake-up, has posed the most serious challenge to Erdogan's Islamic-rooted government since it came to power in 2002.The controversy has widened to implicate Erdogan himself, after recordings were leaked online last week in which the premier can allegedly be heard discussing hiding large sums of cash and conspiring to extort a bribe from a business associate.The government has said the phone recordings are "fabricated".Government has also accused Gulenists of wiretapping thousands of influential people -- including the prime minister, the spy chief and journalists.At an election rally on Saturday, Erdogan blamed Gulen loyalists for "espionage" and "blackmail" and threatened that they would pay a "heavy price". "Confidential and strategic conversations are being wiretapped," he said. Observers say the schools law is the latest move by the government to strike back at Gulen's Hizmet network. Hizmet risks losing millions of dollars in revenue once the Turkish establishments, which offer education to supplement normal schooling, are closed down. Erdogan's government has also recently pushed through legislation tightening state control over the Internet and the judiciary, generating criticism at home and abroad and raising questions about the state of democracy in Turkey.Gulen, who has been living in the United States since 1999 to escape charges of plotting against the secular state by the then-government, has denied any involvement in the corruption probe.The Hizmet movement also runs some 500 private schools around the world.