Bolivia has been in turmoil since presidential voting on October 20. Morales' insistence after 14 years in power that he had been elected to a fourth term in a widely disputed vote prompted massive and violent street protests.
On November 10, after losing the army's backing, Bolivia's first indigenous president resigned and fled to Mexico, before moving on to Argentina.
Morales, a socialist, told AFP on December 24 that he was forced from power by a US-backed coup d'etat aimed at gaining access to the South American country's vast lithium resources.
A survey in late December by the newspaper Pagina Siete found the young coca leaf grower Andronicus Rodríguez, considered Morales' political heir, was leading with 23 percent of voter preference, followed by conservative Carlos Mesa, with 21 percent.
Rodriguez is still awaiting a final decision from his party and from Morales.
Former foreign minister David Choquehuanca also wants to be a MAS candidate.