The campaign to decide who will be President of Colombia for the next four years ends on Sunday.

Campaigning has been marred by spying and bribery scandals that have overshadowed the major issues.

No candidate has been able to whip up much enthusiasm in the run-up to the May 25th vote, and while President Juan Manuel Santos remains the front-runner, a runoff is almost certain.

Al Jazeera's Alessandro Rampietti reports from Bogota.