Zimbabwe to bar Western election observers: paper HARARE (Reuters) - Zimbabwe's President Robert Mugabe will not invite Western observers for a constitutional referendum and general election due this year, state media said on Tuesday, a decision likely to trigger a dispute in his shaky coalition government. Mugabe was forced into a power-sharing deal four years ago with his arch-rival Morgan Tsvangirai, now Prime Minister, after bloody and disputed elections in 2008. The southern African country is due to hold a referendum on March 16 on a new constitution which, if adopted, will pave the way for elections after June when the current presidential and parliamentary terms expire. Foreign Minister Simbarashe Mumbengegwi, from Mugabe's ZANU-PF party, told the state-controlled Herald newspaper that Harare would bar U.S. and European Union observers because of sanctions on Mugabe and his inner circle for alleged human rights abuses. "To be an observer, you have to be objective and once you impose sanctions on one party, your objectivity goes up in smoke," Mumbengegwi, who is responsible for inviting and accrediting foreign observers, was quoted as saying. I do not see why they need to be invited when they have never invited us to monitor theirs. The pronouncement is likely to cause another quarrel within the fractious power-sharing government. Tsvangirai's Movement for Democratic Change has said it will oppose ZANU-PF's plans to hand-pick poll observers. Mumbengegwi said Zimbabwe had already invited referendum observers from the African Union and regional trade blocs the Southern African Development Community and the Common Market for Eastern and Southern Africa. Mugabe, 89, faces a battle to extend his 33 years in power against Tsvangirai, who has promised to fix an economy analysts say has been ruined by policies such as the seizure of white-owned commercial farms to resettle landless black people. Reporting by Nelson Banya; Editing by Ed Cropley and Pravin Char