The two front-runners in Bolivia's presidential election have launched their campaigns.
Coca growers' leader Morales has taken a strong anti-US line
Left-wing candidate Evo Morales - ahead in the polls, received an Andean blessing. If elected, he would be Bolivia's first indigenous president.
His closest rival, the US-educated engineer Jorge Quiroga, opened his campaign with TV and radio spots.
Elections are due on 4 December, but could be delayed by a dispute over the
reallocation of seats.
Mr Morales' rally in La Paz coincided with the anniversary more than 500 years ago of the Spanish conquest of the Americas, which he described as an invasion.
He pledged to improve the rights of Bolivia's indigenous majority and to lift restrictions on coca production.
The indigenous leader - who is known for his strong anti-US stance - also promised to nationalise all Bolivia's energy resources.
The Andean country - the poorest country in South America - has Latin America's second largest gas reserves, and hydrocarbons are its main source of income.
Correspondents say the possibility of a victory for Mr Morales is already causing alarm in Washington.
Mr Quiroga, who served as president in 2001-02 after President Hugo Banzer fell ill, said he would concentrate on getting Bolivia's foreign debt cancelled.
He also demanded that the elections be held in December as scheduled, accusing certain sectors of "putting the democratic system at risk as well as the future of our country."
Last month a court ordered the redistribution of several congressional seats in line with the latest population census.
But the ruling has met with opposition in the provinces set to lose seats and congress has so far failed to agree on the reallocation of seats.
If approved, the changes are likely to affect the campaign of indigenous leader Evo Morales, who enjoys strong support in the highlands but is less popular in the east.