Rodrigo "Timochenko" Londono, the leader of the political party launched by the former Revolutionary Armed Forces of Colombia (FARC), said he feels "betrayed" by the government, which he accused of blocking him from campaigning freely for the May presidential election.

"It might sound harsh, but I want to sincerely launch an SOS for the peace process," he told a press conference.

Londono suspended his campaign on February 9, alleging the authorities were failing to guarantee his security.

He went further in Wednesday's allegations, accusing the government of failing to honor the peace accord that won President Juan Manuel Santos the 2016 Nobel Peace Prize.

"We have seen how small but very powerful forces are uniting to make this historic and beautiful peace process fail," he said.

Colombia is heading toward legislative elections on March 11, then a presidential vote to choose Santos's successor on May 27, with a possible second round on June 17.

It is the first time the FARC will participate in Colombian elections since the group's founding in 1964.

But the guerrilla army-turned-political party says the government is breaking its promises on security for ex-rebels, campaign funding and freeing its jailed members.

Londono, who has around one percent of the vote in opinion polls, denied rumors he was thinking of dropping out of the race.