The guerrillas refashioned themselves as a political party late last year, keeping their acronym, FARC, but changing the name to the Common Alternative Revolutionary Force. They fielded a host of candidates for this year’s elections for the legislature and the presidency that which included some of the most feared guerrilla leaders among their ranks.

The campaigning did not go well. Mr. Londoño was attacked by protesters who pelted his motorcade with rocks, on one occasion doing severe damage to his vehicle. A prominent Senate candidate, Luciano Marín, known by his nom de guerre, Iván Márquez, was forced to cancel campaign events after they were mobbed.

The tensions forced FARC to suspend its campaigning last month, declaring it unsafe. The former rebels blamed right-wing parties, while others in Colombia argued that the group was simply confronting an angry electorate victimized for years by FARC’s kidnappings and deadly attacks. Just a tiny percentage of Colombians say they would consider voting for them.

On Thursday, Félix Antonio Muñoz, a former FARC commander who is running for the Senate, said the atmosphere remained unsafe for the group. “We need to generate new conditions that guarantee that political participation is inclusive,” he told reporters gathered in the city of Armenia on Thursday.

While the group has a diminished profile on the campaign trail, it will still have a presence in the Colombian legislature no matter how the election goes. Under the peace deal, the former guerrillas were guaranteed five seats in the Senate and five in the House of Representatives.