A coalition of Togo opposition parties has agreed on a joint candidate to run in next month's presidential election.
The opposition held protests until Mr Faure stepped down to hold elections
He is 75-year-old Emmanuel Bob-Akitani, the vice-president of the Union of Forces for Change (UFC).
The BBC's Ebow Godwin in Lome says younger members have criticised the decision, saying he is too old to stand against the ruling party's candidate.
Faure Gnassingbe was briefly made president by the army last month when his father, Gnassingbe Eyadema, died.
He later agreed to step down and call elections following violent street protests and international pressure.
The opposition decision was taken after several weeks of discussion amid speculation that exiled UFC leader Gilchrist Olympio himself might return from Paris and run.
Mr Bob-Akitani, who is vice-president of the UFC, came second to Mr Eyadema in the 2003 presidential election with 34.1% of the vote and will face the 39-year-old Mr Faure in the 24 April polls.
Mr Faure was president for three weeks
Mr Olympio is excluded from running because the constitution says candidates must have lived in Togo for at least 12 months before the vote.
He nonetheless did say he was planning to return to Togo and stand in the elections.
Mr Faure - who was president for three weeks following his father's death - will be standing as the ruling party's presidential candidate.
After Mr Faure stood down, West African leaders lifted sanctions it had imposed on Togo.