Tanzanian opposition parties said on Friday that widespread irregularities had taken place in the enrollment of their candidates for elections scheduled for October.
The leading opposition candidate, Tundu Lissu, said dozens of candidates from his party for both parliament and local councils had been disqualified for "unfair reasons".
"We had 3,754 local council candidates...we have lost 30 percent of them," he told crowds during a rally in Dar es Salaam as he called for peaceful demonstrations.
Lissu said also that out of 244 candidates presented for Parliament, 53 had been disqualified and that he had demanded to the electoral commission to reinstate them.
Lissu returned to Tanzania last month after spending nearly three years in Belgium for treatment after he was shot during an assassination attempt.
The presidential and parliamentary elections are scheduled for Oct. 28.
Opposition parties are heading to the polls without a coalition or alliance that helped them gain more votes in the last election.
Tanzanian president John Magufuli, who has ruled the country since 2015, will face 14 challengers in the elections, with analysts saying a divided opposition is likely to ensure he will win a second term.
Another opposition party, Alliance for Transparency and Change (ACT-Wazalendo), also denounced on Friday that most of their candidates had been "objected".
The National Electoral Commission (NEC) said in a statement on Friday evening that in 18 constituencies candidates had no opposers because of "several reasons". The commission did not address the allegations of irregularities from the opposition.
Magufuli’s party has ruled Tanzania since independence in 1961. When he came to power in 2015 he promised to end corruption and develop the country's infrastructure.
He has been accused by rights groups and opposition politicians of muzzling the press and intimidating political rivals ahead of October's vote, accusations the administration denies.