By Daniela Desantis
ASUNCION (Reuters) - Security forces surrounded Paraguay's Congress on Tuesday while lawmakers argued over a possible change in law that would allow President Horacio Cartes to run for re-election, a move that the opposition says would weaken democratic institutions.
A bill allowing presidents to run for a second five-year term was defeated in the legislature last year.
This week a group of senators asked for a special session that the opposition interpreted as the start of a new campaign by Cartes and his coalition to enable presidential re-election.
Opposition leaders and dissident members of Cartes' party accused him of shaking the country's democratic foundations by ordering that Congress be surrounded by police and soldiers.
"We have to safeguard the republic," said Senator Blanca Ovelar, a member of Cartes' Colorado Party who has broken with the president. "This is a situation of institutional breakdown."
Soft drink and tobacco mogul Cartes was elected to a five-year term in 2013. His strongest backers want him to be allowed to run for another term next year. Critics say a constitutional change aimed at benefiting a sitting president would be unfair.
The Inter-American Development bank is holding a regional meeting in Asuncion starting on Thursday. Security consultancies International SOS and Control Risks issued a statement warning conference goers to avoid the vicinity of the Congress building in case tensions escalate.
On Wednesday, thousands of subsistence farmers are expected to come to capital city Asuncion to lobby for agrarian reform. Protests in favor of more protections for small farmers are held at Congress every March.
Cartes' supporters in Congress said they will stick with their petition for a special session aimed at changing legislative rules, which could lead to the revival of the re-election bill. The rules as they stand would disallow Congress from taking up the question of re-election until a year has passed from last August, when the proposal was rejected.
"I am so surprised at this abuse of power in not allowing the change in rules. We want the participation of the people and we are going to stay here as long as necessary," said Senator Lilian Samaniego, a Cartes ally.
(Writing by Hugh Bronstein; Editing by Richard Chang)