Outgoing president calls for protection of peace as several former rebel fighters become legislators.

Colombia’s former FARC rebels have taken their seats in Congress as part of a peace deal after more than five decades of war against the government.

At the swearing-in ceremony on Friday, outgoing President Juan Manuel Santos, who signed the landmark agreement in 2016, urged the country to protect nascent peace and put an end to violence.

“Many – we must admit it – don’t like seeing them in this place of debate and civility,” Santos said.

“In my case, and I’m sure it’s shared by millions of Colombians, it fills me with satisfaction that those who for more than half a century fought with arms against the state and its institutions, today submit to the Constitution and the laws of Colombia, as we all do,” he added.

“Welcome to this temple of democracy!”

Santos urges the nation to protect the nascent peace [Juan Pablo Pino/Reuters]

Under the terms of the 2016 peace deal between the FARC and the government, the group formed a political party, kept its famous acronym as the Revolutionary Alternative Common Force, and was awarded five seats each in the 108-member Senate and the 172-member lower house through 2026.

Zeuxis Pausias Hernandez, a FARC leader also known as Jesus Santrich, was unable to take his seat in the House of Representatives because he is under arrest on charges of drug trafficking. He was detained on April 9 after the US justice department requested his extradition.

Protesting his detention, another prominent FARC leader, Ivan Marquez, withdrew from his seat, accusing the government of breaching the peace deal. Former FARC rebel, Israel Zuniga, also known as Benkos Bioho, took his seat instead, according to local media.

Colombians deeply divided

The peace accord, for which Santos won the Nobel Peace Prize, has deeply divided Colombians, with conservatives saying it goes too easy on the former rebels.

Right-wing President-elect Ivan Duque will replace Santos next month and seek to guide key economic reforms – pension and tax – through the new Congress. He will also try and adjust the peace accords.

Duque and his Democratic Center party want to scrap an amnesty for FARC commanders who committed crimes, including engagement in the cocaine trafficking that helped bankroll the group, and prevent them from participating in politics until they serve prison sentences.

Duque, a 41-year-old protege of former President Alvaro Uribe, whose hardline battle offensive against the rebels helped push them to the negotiating table, has said he is incensed that there would be “criminals” in Congress shaping laws after decades of kidnapping, extortion and killing.

He said he would alter the peace accord by forging alliances in Congress, where his party holds just 51 of 280 seats, and by generating a national consensus.

The peace deal was signed in Cuba in 2016 [Colombian Presidency handout via Reuters]

The FARC’s presence in Congress promises to create tension. Uribe, whose hatred for the rebels was born after his father was killed in a botched kidnapping, has a seat in the Senate.

He and his party will likely seek to block votes on initiatives put forward by the FARC for having participated in a conflict that left 220,000 dead and millions displaced.

But while Duque may make minor changes to the peace accord, it would be almost impossible for him to make substantive alterations, analysts have said.

The left parties have said they will join forces to seek to block any changes.

“We want to build a democratic, intelligent and collective opposition with aspirations to govern,” Angela Maria Robledo, a lower house legislator from the leftist coalition of parties, told reporters.

Left-wing Gustavo Petro, Duque’s rival in the presidential race, will lead the opposition in the Senate.