BOGOTA (Reuters) - The leader of Colombia’s FARC political party, former Marxist rebel commander Rodrigo Londono, will undergo heart surgery, the group said in a statement on Friday.

FILE PHOTO - Colombia's FARC (Revolutionary Armed Forces of Colombia) leader and presidential candidate Rodrigo Londono, also known as Timochenko, speaks during a news conference in Bogota, Colombia February 28, 2018. REUTERS/Jaime Saldarriaga

Londono is a presidential candidate for the party, the unarmed reincarnation of the Revolutionary Armed Forces of Colombia (FARC) guerrilla group, in May elections.

Known by his rebel nom de guerre Timochenko, he was hospitalized on Thursday with chest pains. FARC senate candidate Carlos Antonio Lozada told reporters outside Bogota’s Shaio Clinic on Friday that Londono was conscious and confident the surgery will go well.

The group did not provide details of when the surgery will take place. The clinic said in a statement that doctors felt surgery was necessary after conducting tests and reviewing Londono’s clinical history.

The 59-year-old Londono has long suffered heart problems and underwent a prior surgery in Cuba while the group was negotiating the terms of a 2016 peace deal with the government.

He was taken to hospital after his daily exercise routine Thursday, the group said.

The FARC kept its Spanish-language acronym after demobilization but changed its name to the Revolutionary Alternative Common Force.

Londono suspended campaigning last month due to security concerns after angry protests disrupted campaign stops.

The FARC was known during its long-running armed conflict for kidnappings, bombings and forced displacements. Many Colombians believe its members should be in prison, not campaigning, and recent opinion polls have shown Londono has as little as 1 percent support.

The party has focused its political platform on fighting poverty.