In an interview with Britain's Daily Telegraph, Tsvangirai -- who is running for a third time for president against Mugabe -- criticized Mugabe for calling the July 31 election without consultation with political allies, and charged the government failed to implement agreed-upon election reforms.
Tsvangirai joined Mugabe in a governing coalition after Mugabe won a 2009 election that provoked violence in which hundreds of people were killed. Widespread mob violence prior to the last two elections also resulted in the deaths of hundreds of people.
Tsvangirai told the newspaper if he does not win the presidency in this month's election he will decline any overture to remain as prime minister.
"The people of Zimbabwe are desperate to start on a new plate and actually give proper direction and proper policy direction to revive this economy, give people hope and actually start all over again," Tsvangirai said.
Accusing Mugabe of desiring to "retain power by whatever means," Tsvangirai said the Mugabe government "doesn't believe in a free and fair vote" – and he accused the government of inflating voter rolls with the names of dead voters to provide an opportunity for rigging the outcome.
"From our analysis you have 100,000 people above the age of 100," he said.
"The voters' roll has become the center for the rigging mechanism."