CARACAS, Venezuela — President Hugo Chavez asked supporters to propose a constitutional reform that would allow him to seek indefinite re-election and govern through 2019, giving him more time to build a socialist economy in Venezuela.

"We are going to begin the national debate," the former paratroops commander told a crowd of red-clad government supporters at a rally in Caracas on Sunday.

Chavez, who was first elected in 1998, is barred from running again when his term as president expires in 2013.

Venezuelan voters last year rejected a sweeping package of constitutional changes that would have ended presidential term limits, with many of Chavez's opponents warning that he intends to be president for life.

Any new attempt at a reform, which must be approved in a countrywide referendum, would open a new front for tensions between government-backers and their political rivals.

Chavez also threatened Sunday to expel Colombia's top diplomat in Maracaibo, Venezuela's second largest city, after he privately welcomed opposition victories in five key races during last week's gubernatorial and municipal elections.

In a private telephone conversation apparently recorded by Venezuelan intelligence agents, Carlos Galvis called the opposition's gains "very good news." The recording was then broadcast on state television by talk show host Alberto Noria.

Chavez urged Colombian President Alvaro Uribe to recall Galvis. "If not, I'll expel him," he warned.

Months of sniping between Caracas and Bogota threatened trade and unleashed a diplomatic crisis earlier this year, when Colombian officials accused Venezuela's government of supporting leftist Colombian guerrillas.

But ties between the two countries had improved in recent months.