Malawi Vice President Saulos Chilima was elected head of the United Transformation Movement (UTM) party on Monday, paving way for him to challenge President Peter Mutharika in May elections.Chilima was handpicked by Mutharika to run alongside him in the 2014 elections on the Democratic People's Party (DPP) ticket.But Chilima quit the DPP in June to form the UTM, citing corruption, nepotism and cronyism in the ruling party.About 900 delegates gathered in Lilongwe for the UTM's first convention since the party was founded five months ago."We cannot continue in the 'business-as-usual' manner in which our country has been run," Chilima said after being elected unopposed."Our calling is a call to service and to reclaim Malawi."Under the constitution, the vice president cannot be sacked by the president. * Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook. Chilima, 45, is seen as a young challenger to Mutharika, 79, who won the election in 2014, two years after his brother, Bingu wa Mutharika, died while serving as president.Chilima's chances of launching a serious challenge to Mutharika remain uncertain.Food shortages, power outages and ballooning external debt have hurt the president's popularity."Chilima could be a dark horse as people are increasingly disturbed by the the current government," said Switzerland-based political analyst Onjezani Kenani.Joyce Banda, 69, is back in the country after a four-year absence, hoping to reclaim the presidency that she held between 2012 and 2014.Malawi is one of the world's most aid-dependent countries and its economy is mainly based on subsistence farming.