JUBA, Sudan: South Sudan's president told U.N. Security Council envoys his region might have to hold its own independence referendum if the north disrupted next year's vote, a visiting U.N. ambassador said on Thursday. Such a move would enrage Khartoum, which wants to keep Africa's largest country in one piece. Southerners are about three months away from a referendum on whether they should form Africa's newest country or stay united with the north, their foes in a decades-long civil war that ended in 2005. Preparations for the vote are behind schedule and the south has repeatedly accused the north of trying to delay the ballot to keep control of the region's oil, a charge Khartoum denies. Analysts have warned there is a risk the parties could go back to war. “He (Southern president Salva Kiir) was not going to declare UDI (a unilateral declaration of independence),” Britain's Security Council ambassador Mark Lyall Grant told reporters, describing what Kiir told envoys during a meeting in the southern capital Juba on Wednesday. “But if there is a delay, a politically induced delay by the NCP (the north's dominant National Congress Party) for the referendum, then it might be necessary for the south to hold their own referendum,” he said. Lyall Grant said a new timetable, laying out preparations for the referendum ahead of its scheduled start date on Jan. 9, 2011 was “very ambitious”. The ambassador said the envoys would use their visit to Sudan to show a united front and press northern and southern leaders to hold the vote as scheduled. “All members of the Security Council are saying they are united behind pressing both parties to make the necessary preparations ... to allow the referendum to take place on time, be credible and be respected by all parties,” Lyall Grant told reporters. The referendum, and a separate vote on whether the disputed area of Abyei should join the north or south, were promised in the 2005 Comprehensive Peace Agreement that ended Africa's longest civil war.