FACTBOX: Colombia's bribery scandal

(Reuters) - A former Colombian lawmaker was sentenced last week to almost four years of house arrest for accepting illegal favors in exchange for supporting the constitutional amendment that allowed President Alvaro Uribe to run for and win re-election in 2006.

As the country awaits charges to be filed against the high government officials who allegedly offered bribes to ex-Congress member Yidis Medina, Uribe says he will use a voter referendum to affirm his mandate rather than wait for the courts to rule on the legality of his re-election.

Following are some key facts about the bribery scandal, dubbed "Yidis-politics" by the local media, and what is known so far about Uribe's referendum proposal:

CONFLICT WITH COURTS

The Supreme Court, when it sentenced Medina, asked the Constitutional Court to rule on the legality of the re-election process. The combative U.S.-backed president's move toward a referendum throws politics into turmoil and turns his long-simmering feud with Colombia's courts into an open clash.

Uribe has regularly sparred with the judiciary over his peace negotiations with right-wing paramilitary militias, thousands of whom have demobilized under a deal offering them reduced jail terms for crimes including mass murder.

Uribe says the courts meddle in his policies due to political bias and they say he is too unilateral.

THE EX-LAWMAKER:

Yidis Medina was a junior member of the lower house in 2004 when she served on the Constitutional and Political Affairs Committee, which was split with 16 members favoring the bill allowing Uribe to seek a second term and 16 against. Three members, including Medina, were undecided, making her vote key.

Medina, a Conservative party member who helped form Uribe's coalition, says government officials bribed her into supporting the bill by promising she could name friends to local government commissions in her home province, Santander.

At one meeting at the presidential palace, Medina said Uribe walked in and asked her to vote for the re-election amendment, assuring her that his administration would honor its commitments to her. But the government did not deliver on all its promises, which she says led her to go public.

LEGAL DEBATE:

The main question is whether a referendum can be called to rerun an election that has not yet been officially invalidated. Colombia's Constitutional Court is weighing whether or not to review the passage of the re-election amendment to determine if it was legal.

THE REFERENDUM:

Administration officials were at work on Monday drawing up the language of the referendum question. Once the text is ready, it will be presented to Congress for approval and, if passed, go to a popular vote. Analysts said it was too soon to predict when the measure might be ready to go to the voters.

OPPOSITION REACTION

The government says the proposed rerun of the 2006 election would only validate Uribe's current term in office, which ends in 2010.

Political opponents say they suspect the referendum will be used by Uribe to leapfrog court rulings, damage the constitutional balance of powers and advance the idea of him being allowed to extend his time in power.

(Reporting by Hugh Bronstein; Editing by Cynthia Osterman)