Chavez threatens to cut U.S. oil supply over vote

By Brian Ellsworth

CARACAS (Reuters) - Venezuelan President Hugo Chavez threatened on Friday to cut off oil supplies to the United States if the superpower interferes in a referendum this weekend over whether he can run for re-election indefinitely.

Chavez also sought to fire up his core backers for a tight vote on Sunday by threatening to break off diplomatic ties with Spain unless the former colonial power's king apologizes for telling him to shut up at a summit meeting this month.

Chavez issued the warnings at a massive rally closing a campaign that is the toughest of his political career.

The Cuba ally, one of the world's leading critics of Washington, has frequently issued conditional threats about stopping crude sales to its top customer.

But Venezuela has remained the No. 4 oil supplier to the United States despite fraying ties.

The self-styled socialist revolutionary frequently says Washington plots to topple him. The U.S. government denies the allegations.

Conflicts with Western powers help his supporters rally around a president they perceive to be under threat from foreign enemies, political analysts say.

On Friday, Chavez said the Bush administration was colluding with the opposition to cry fraud after the referendum to stoke violent protests and provoke a coup.