Prominent Tanzanian opposition figure Tundu Lissu is expected to return home on Monday, three years after surviving an assassination in the capital, Dodoma.
Mr Lissu, 52, was stripped of his parliamentary seat while receiving treatment in Belgium for gunshot wounds sustained in the attack.
He is expected to arrive in the commercial city of Dar es Salaam and has asked the government to guarantee his safety.
Mr Lissu has declared interest to challenge incumbent John Magufuli for the presidency and had picked nomination papers from his Chadema party through representatives.
Tanzania is preparing to hold general elections in October and President Magufuli is vying for a second five-year term.
Human rights groups had asked government to facilitate Mr Lissu’s safe return.
BBC’s Sammy Awami told Newsday programme that Mr Lissu is expected to start the process of getting the party’s nomination for the presidential race upon his return