Religious organisations in Tanzania face having licenses revoked.
Tanzanian churches whose preachers "mix religion with politics" face being closed down according to a statement issued by the country's home affairs ministry.
The warning comes days after criticism from the pulpit of Tanzanian president John Magufuli, whose tough leadership style has earned him the nickname "The Bulldozer".
Zachary Kakobe, the self-proclaimed bishop and founder of the Full Gospel Bible Fellowship Church, used a Christmas sermon in Dar es Salaam to say that Tanzania was "turning into a one party state".
Subsequently Tanzania's religious organisations, which require a licence from the home affairs ministry, were warned that their licences would be revoked if their clerics dabbled in politics.
Four newspapers were shut down in Tanzania in 2017, on charges of publishing false information or inciting violence, while individuals have been prosecuted for allegedly insulting President Magufuli on social media. Political protests and rallies in Tanzania were suspended in 2016, with political campaigning now only permitted during elections.
Magufuli, whose crusade against corruption has seen him fire dozens of government officials, has won praise from some western donors but is accused by critics of being increasingly authoritarian, a charge he denies strongly.