Bolivia's former President Evo Morales insisted on Sunday that he would press on with a hunger strike until the government of his protégé-turned-rival agreed to a political dialogue.

Morales' supporters have blocked roads and caused disruptions around the country in protest against what they say is the government's political persecution of the former Bolivian leader.

Morales, a larger-than-life figure still towering over Bolivian politics five years after his ouster, spoke on his third day without food from Chapare, Bolivia’s rural coca-growing region that serves as his stronghold.

“My fight is to improve the situation in the country and to start a dialogue without conditions on two fronts, one economic and one political,” Morales told reporters from the office of the coca growers’ federation that he long has led.

The former president said he began his hunger strike on Friday in the hope that "international organisations or friendly governments" would facilitate talks with his political nemesis, President Luis Arce .

Tensions have surged over the past three weeks since pro-Morales supporters set up crippling roadblocks aimed at rebuking Arce — Morales' former economy minister with whom he is now vying to lead Bolivia’s governing socialist party into next year’s elections.

Since mid-October, protesters have choked off major highways in defiance of an attempt by Arce's government to revive a 2016 statutory rape case against Morales, an ethnic Aymara who was the first member of an indigenous community to become the president of Latin America’s only indigenous-majority nation.

Since then, the disruptions in transport have cost the South American country more than US$1.7 billion, according to Bolivia's government.

Morales has denied any wrongdoing and rejects the charges as politically motivated.

“My crime is being indigenous,” he said on Sunday. (AP)