Venezuelans have voted in a referendum on more power for President Hugo Chavez.

Three exit polls predict that he will win the referendum on constitutional amendments by six to eight percent of the vote.

A 'yes' vote will abandon limits on how long Mr Chavez can rule as President.

The reforms will also give him control over the central bank and foreign currency reserves, reduce the workday to six hours and extend social security benefits to self-employed workers such as street vendors.

Mr Chavez, who has easily won one election after another against a shattered opposition, is attempting to deepen his self-styled revolution by reforming the constitution.

Most of the polls are showing a very close race between backers of the referendum and those believe it offends democratic principles.

Campaigning had been marred by violence, but early voting appeared to be orderly, with Mr Chavez saying he would accept the results, whatever.