Tanzania's President John Magufuli has been challenged to a televised debate by his rival Tundu Lissu ahead of next month's election.
President Magufuli is seeking a second five-year term amid concerns of increased repression of opposition parties.
Mr Magufuli has not yet responded to the challenge.
Mr Lissu, the leader of Chadema party, said a televised debate of the presidential candidates will be "healthy for the country's democracy".
He told a campaign rally that President Magufuli shouldn't be afraid of debating a person who has never been a president like him.
He tweeted a footage of his Swahili address to the rally:
Natoa rai kwa Mgombea Urais wa CCM na vyombo vyetu vya habari, kufanikisha mdahalo kuhusu mustakabali wa Taifa letu la Tanzania ????????! Calling on the incumbent President John Magufuli for a public presidential debate!
— Tundu Antiphas Lissu (@TunduALissu) September 13, 2020
Retweet ???? kama unakubaliana nami!!#TunduLissu2020 #SasaBasi pic.twitter.com/DdNEQpKuZQ