Bolivians at the ceremony cheered the assembly's launch

A wide range of groups are represented on the constituent assembly - including coca-growers, trade unions and miners.

Mr Morales became Bolivia's first indigenous president last year.

However his supporters lack the two-thirds majority required to change the constitution and will need the support of opposition groups.

Following his election in December, Mr Morales promised to undo centuries of dominance by descendants of Europeans.

He told delegates at the ceremony in the city of Sucre: "I really feel that right here starts a new Bolivian history, a history where there is equity, a history where there is no discrimination."

Bolivia's current constitution was adopted in 1967 under President Rene Barrientos Ortuno, who originally came to power in a coup before being elected.

A key sticking point in a new constitution could be the demand for greater regional autonomy led by the wealthy eastern province of Santa Cruz.