Tanzanians will pick a new president and parliament on Oct. 25, officials said on Monday, in a national election likely to be dominated by the ruling party despite rising anger at poverty and corruption.
President Jakaya Kikwete is due to step down from the helm of east Africa's second-biggest economy after two terms – the limit set out in the constitution.
Tanzania's main opposition parties have promised to unite behind a single presidential candidate to replace him.
But analysts have said that plan could be hobbled by long-running in-fighting over policies and leadership, and the ruling Chama Cha Mapinduzi (CCM) party would still likely win through, albeit with a reduced margin.
Front-runners to become CCM candidate include former prime minister Edward Lowassa.
"Only five individuals among the [party's] presidential hopefuls will get a real shot at the post, but about 15-17 individuals are expected to enter the race this year," said Ahmed Salim, senior associate at consultancy Teneo Intelligence in a note to clients.
Tanzania has held a series of relatively peaceful elections since the reintroduction of multi-party polls in 1995 – though political tensions are rising in other parts of the continent as long-running leaders approach term limits.
The decision by the president of neighboring Burundi last month to run for a third five years in office has triggered weeks of often violent protests and a failed coup.
The new election was widely expected in October, though a specific date had not been announced.
Campaigning for this year's presidential, parliamentary and local authority elections will run from August 22 to October 24, the chairman of Tanzania's national electoral commission, Daminan Lubuva, told Reuters.
"We expect to conclude the ongoing registration of voters towards the end of July or latest by the second week of August," he added.
Opposition leaders have said the slow pace of voter registration, which has already held up a referendum on the constitution this year, could disrupt the polls. A new date for the referendum would be announced after voter registration finished, Lubuva said.