Tanzania's politically volatile Zanzibar island votes in a referendum Saturday to install a power-sharing government aimed at ending the archipelago's persistent election unrest. The ruling Chama Cha Mapinduzi (CCM - Revolutionary party) and the main opposition Civic United Front (CUF) are backing the deal and have called on voters to endorse it. A new form of government would see Zanzibar have a president with two deputies. The first vice president would be from the party which comes second in the polls and the second from the winning party. Ministers are to be allocated on a proportional basis. If passed, Zanzibar's constitution will then be amended to pave the way for a unity government in readiness for general elections on October 31. 'Vote 'yes' in the referendum so that we remain united. We need to work together and heal hatred caused by unnecessary political conflicts after every general election,' Zanzibar President Amani Karume told a gathering this week. 'Zanzibaris should not allow a return to division,' CUF leader Seif Sharif Hamad told selfnews. 'We need to build our country which has been ruined by the prolonged conflicts. I hope that the majority people of Zanzibar will vote 'yes'.' A positive outcome of the July 31 referendum will propel Zanzibar to the league of African governments to have negotiated power-sharing accords in the aftermath of disputed elections. It will however be set apart from Kenya and Zimbabwe by making the deal a constitutional provision ahead of its next elections. The Indian Ocean archipelago comprises three islands of Unguja, Pemba and Mafia. Mafia is however administered by mainland Tanzania. Zanzibar declared independence on January 12, 1964 after a bloody revolution that ended several centuries of rule by Arab sultans. Three months later, it merged with mainland Tanganyika to form the United Republic of Tanzania, but maintained a semi-autonomous government with its own president, constitution, flag and national anthem. Rivalry between the CCM and CUF has been bitter and at times bloody since the re-introduction of multi-party politics in 1992. The CCM has won all subsequent elections in 1995, 2000 and 2005, sparking protests by the opposition, which repeatedly charged that results were rigged in favour of the ruling party. At least 30 people were killed in January 2001 during clashes between police and supporters of CUF in Zanzibar and Pemba. Dozens of Pemba residents fled to Kenya. Tanzanian President Jakaya Kikwete deplored the perennial enmity between the Zanzibar parties, which he said had also divided the society. 'People of the same island and even clan stopped talking to each other,' he recently told parliament. 'CCM or CUF members failed to turn out at funerals of relatives who belonged to a different party. This is too bad. I am pleased that things are now changing for the better.' Some 400,000 voters have been registered to take part in Saturday's referendum, whose results are to be announced two days later. Observers from the European Union and the US will monitor the exercise. Zanzibar, an idyllic travel destination with palm fringed beaches and historic sites, is home to around 1.2 million people. 