BOGOTA, Colombia — Former President Alvaro Uribe fanned widespread resentment of Colombia’s largest rebel group as he crisscrossed the country, campaigning for weeks against a peace deal he said would appease “terrorists” or lead the country down the path of communist Cuba.

But Colombians now look to the conservative hardliner as a potential savior of the accord that hangs by a thread following voters’ shocking rejection of the deal in a referendum Sunday.

Colombia’s political landscape was upended by the referendum. President Juan Manuel Santos, who has staked his presidency on trying to end the half-century conflict, was weakened by the vote while Uribe was seen as the big winner.

After trashing the agreement as a gift to the Revolutionary Armed Forces of Colombia, whose rebels are blamed for dozens of atrocities, Uribe sounded conciliatory in victory and offered to be part of a “national accord” aimed at ending the conflict.

Santos quickly accepted the offer and the two met Wednesday at the presidential palace that Uribe occupied in 2002-10. The meeting was in itself a political milestone as the two men hadn’t seen each other since 2011.

“Colombians, we’re very close to achieving peace,” Santos said after the meeting. “If everyone shows good will, and contributes with responsibility, realism and celerity, we will get there.”

Talks between the government and the opposition to alter the accord are a high-stakes gamble that could fail if FARC leaders don’t go along.

Uribe’s hatred of the FARC is personal. Rebels killed his father in a failed 1983 kidnapping attempt at the family’s farm in Antioquia state. Shortly afterward, Uribe abandoned his legal career and entered politics, finally getting revenge two decades later as president when he leveraged U.S. military support to drive the rebels back to the edge of the jungles.

Santos was Uribe’s trusted defense minister during some of the government’s biggest military blows against the rebels, including a 2008 raid into Ecuador that killed a top FARC commander and the rescue of three Americans held hostage for five years.

But the two angrily split shortly after Uribe helped elect Santos as his successor. Uribe regularly blasts Santos to his 4.5 million followers on Twitter — almost the same number as the president — to the point that Colombians joke it would be easier for Santos to achieve peace with the FARC than patch things up with his former ally.

Before the referendum, polls initially showed the “yes” vote winning by an almost 2-1 margin. But Uribe took on the government’s well-funded publicity blitz with a grassroots campaign giving voice to millions of Colombians, especially the poor and rural voters, who bristled at provisions in the 297-page accord that spared jail time for rebel leaders who committed violent crimes and set aside congressional seats for FARC members.

“Uribe is a political animal who better than anyone can look into the soul of the Colombians and speak a language they understand,” said Jaime Castro, a former mayor of Bogota who opposed the accord but is also critical of Uribe’s strident rhetoric.

On the day of the peace deal’s signing ceremony in Cartagena last week, as world leaders and U.N. Secretary-General Ban Ki-moon were arriving, Uribe spoke to a crowd of some 500 supporters gathered outside the historic city’s colonial ramparts.

“The democratic world would never allow Bin Laden or those belonging to ISIS to become president,” Uribe said standing in the blazing midday sun on the back of a pickup truck. “So why does Colombia have to allow the election of the terrorists who’ve kidnapped 11,700 children or raped 6,800 women?”

In the past, the FARC has expressed a begrudging respect for Uribe, with rebel leader Timochenko last May inviting to meet anywhere the former president wanted to voice his concerns about the negotiations.

“President Uribe, we are willing to talk calmly with you about the future of our nation,” Timochenko wrote in an open letter. “With hate you can’t go anywhere. We’re very clear that passion and polarization are bad influences, that nobody is the owner of the absolute truth and that peace must be built collectively.”

Uribe never responded to the invitation. It’s now unclear if the FARC rebels will sit down with their longtime enemy.

A FARC representative, who spoke on condition of anonymity to prevent disrupting attempts at dialogue, said rebels could be reluctant to renegotiate the accord with someone who long sought their extermination. The rebel negotiator said Uribe is likely to support stiff penalties for guerrillas, who insist they not serve jail time.

Uribe, in the past, supported some concessions to rebels that he now criticizes as acts of impunity, fueling hope a compromise could be reached. As a lawmaker in 1992, he sponsored legislation giving a “total pardon” to M-19 guerrillas, an unrelated rebel group, who attacked the Supreme Court and killed 11 magistrates.

Still, some worry that despite his offer of conciliation, Uribe could ultimately obstruct peace efforts to maximize his political advantage ahead of the 2018 presidential election. Uribe is banned from running again, but he’ll likely dominate any candidate from his Democratic Center party.

“I would not be surprised if Uribe pressed for an agreement with the FARC on his own terms, one that is acceptable to most Colombians. In this way he would wrest credit for being the peacemaker from Santos,” said Michael Shifter, who attended the peace signing ceremony as president of the Washington-based Inter-American Dialogue. “Nothing would make him happier. Egos and petty politics will have a great deal to do with how this all works out.”

Joshua Goodman is on Twitter: . His work can be found at .