Article published on the 2008-09-28 Latest update 2008-09-28 13:24 TU
The government has predicted a 70 per cent yes vote, while private opinion polls predict 60 per cent for and 24 per cent against.
The 444-article constitution would increase the president's powers, allowing two consecutive terms of office, four-year terms and the power to dissolve Congress and call early elections.
President Rafael Correa argues that the powers are necessary to prevent a repetition of his political confrontations with the previous Congress, which was controlled by the opposition, and with the former governor of the central bank.
The new constitution would also close down all foreign military bases, which would force the US to move its regional anti-drugs operation, currently run from an air-base in the port city of Manta.
Opposition leader Jaime Nebot, who is mayor of the town of Guayaquil, claims that the new legal framework create a centralised government that would threaten private property.
About 9.7 million voters are elegible to take part in the referendum.