(ANSA) - BELGRADE, 10 SET - The Specialist Prosecutor's Office (SPO) has asked the Kosovo Specialist Chambers in The Hague to sentence former Kosovo President Hashim Thaçi to six years in prison for obstructing justice. During closing arguments, prosecutor Joshua Hafetz emphasised that the charges had been proven and constituted criminal offences, and that any attempt to interfere jeopardised the proper administration of justice. Meanwhile, the defence has requested Thaçi's acquittal. Closing arguments are scheduled to conclude on September 14. Thaçi and the others are accused in this separate trial of attempting to influence prosecution witnesses in the main case against them, which is also before the Specialist Chambers. They are charged with war crimes and crimes against humanity against Serb civilians during the 1998-99 Kosovo war, and they have pleaded not guilty. Thaçi and three other former KLA leaders could face up to 45 years in prison if it is proven they ordered or knew about the crimes. The verdict is expected on Wednesday, September 16, and it could have a significant political impact in Kosovo. (ANSA).