Tanzania’s Vice-President Emmanuel Nchimbi has been expelled from the ruling Chama Cha Mapinduzi party for alleged indiscipline after resigning from office, becoming the first vice-president in the country’s history to step down. The move suggests a widening rift with President Samia Suluhu Hassan and comes amid renewed debate over constitutional reform and political freedoms following a disputed election.

Nchimbi, 54, had served for 10 months and recently urged Tanzanians to seek a new constitution; the party gave no further details of the allegations against him. Energy Minister Deogratius Ndejembi, 43, has been nominated to replace him, subject to parliamentary approval, while Nchimbi’s resignation takes effect at the end of the following week. Samia and Nchimbi won 98% of the vote in last October’s election, which the main opposition boycotted and after which an official inquiry said at least 500 people died in unrest.