Bolivian President Evo Morales has agreed to serve another term as head of his country's main coca-growers union.
Mr Morales is seeking greater commercial uses for coca leaves
Accepting the nomination, Mr Morales told the union's conference that it would enable him to keep in touch with the people while in office.
But critics said the move could be unconstitutional and would leave him open to allegations of bias.
Mr Morales has led coca-growers for 18 years - a position that put him on the national political stage.
His mandate was renewed by consensus, without a vote. It is his sixth consecutive term as leader of the union.
In his address at the conference in the central city of Cochabamba, Mr Morales said he was proud of being a coca-grower.
He praised the "maturity" of farmers for agreeing to limit their coca plots to four-tenths of an acre - a traditional unit of area in Bolivia, known as Cato.
Mr Morales has opposed US-funded programs to eradicate coca crops, but has pledged to end drug-trafficking in Bolivia.
Coca is used to make cocaine, but also has widespread ceremonial and medical uses in Bolivia.
Many people in rural areas use the leaves in tea, or chew them to ward off hunger and altitude sickness.
Mr Morales, who was elected in December 2005 as the country's first indigenous president, is seeking greater commercial uses for the plant.