DODOMA — A former Tanzanian prime minister who was the front-runner in a race to be the ruling party's presidential candidate has been dropped from a shortlist for the post, triggering a rift among senior members in the party, officials said. The Chama Cha Mapinduzi (CCM) party has ruled Tanzania for five decades and the person nominated to be its candidate is almost assured of winning the election in October, taking over from President Jakaya Kikwete who has served a maximum two terms. Edward Lowassa, 61, was seen as leading the party race but is a divisive figure after resigning as premier in 2008 over corruption allegations in the energy sector, allegations he denied. The CCM's central committee, chaired by the president, drew up a shortlist of five candidates without naming Lowassa late on Friday in the Tanzania capital Dodoma from 38 hopefuls. Final voting on a single candidate is expected on Saturday. Party officials who announced the shortlist did not say why Lowassa was left out. But the party has promised to clamp down on corruption, seen as a major obstacle to business and an issue that Western donors had said needs to be tackled. Tanzania has been one of Africa's most politically stable nations and has not been torn by the debate raging in parts of the continent, where some presidents have been eying third terms despite constitutional restrictions. The CCM usually keeps any internal party debate behind closed doors, but three out of 32 members of the CCM central committee publicly objected to the decision to oust Lowassa, who had backed Kikwete when he made his bid for president in 2005. “We disassociate ourselves from this decision,” Emmanuel Nchimbi, a member of the party's central committee told reporters, adding the party constitution “dictates that the most popular candidate should be picked as presidential nominee.” One CCM official told Reuters that Lowassa's supporters in the party's 378-member national executive committee could challenge the decision to pass over Lowassa's bid at Saturday's party congress. The short-listed candidates are Foreign Minister Bernard Membe, former senior UN official Asha-Rose Migiro, Works Minister John Magufuli, African Union ambassador to the United States Amina Salum Ali and deputy communications minister January Makamba, a former Kikwete aide. Lowassa has yet to comment. One aide said he could still make a bid for the presidency but as an opposition candidate. The main opposition parties promised last year to field a single candidate in the Oct. 25 race, but experts say they may struggle to overcome years of mutual suspicion and infighting. — Reuters