Venezuelan President Hugo Chavez has said he will accept the result of Sunday's referendum on proposed changes to the country's constitution that would greatly increase his power.
Public opinion polls indicated the result was too close to predict.
The proposed constitutional changes would eliminate presidential term limits and grant the government sweeping powers in the event of a national emergency.
Thousands of people marched last week in Caracas in protests against the proposed changes. The following day, thousands rallied to support President Chavez.
Mr. Chavez has said he believes the United States would interfere with the election, and he threatened to cut off oil sales to the US if it does.
Today, a leading US senator rejected Mr. Chavez's allegations. Democratic Senator Carl Levin said the United States is not seeking to destabilize Venezuela.
Mr. Chavez said if voters pass the constitutional changes, he is prepared to stay in power until 2050.
The referendum would also shorten the work day and extend social security programs to more workers.
Opposition parties, human rights groups and Roman Catholic Church leaders in Venezuela oppose the changes because of what they say is an unprecedented concentration of power in the president's hands. Mr. Chavez argues that revising the constitution is necessary to strengthen the people's voice in government.