Thousands of Sandinista militants on Tuesday bid goodbye to Tomas Borge Martinez, the last surviving founder of the guerrilla movement that overthrew Nicaragua’s U.S.-backed right-wing dictatorship in 1979 and replaced it with a leftist government also criticized for repression.

Mourners wearing hats and T-shirts with Sandinista logos waited in snaking lines up marble stairs to the second floor of the National Palace of Culture where Borge’s casket was surrounded with dozens of floral arrangement while revolutionary music blared in the plaza outside.

Most of the mourners came with their neighborhood organizations or unions.

“We wouldn’t have had a revolution without him,’’ said Glenda Perez, a social science university professor and Sandinista militant.

President Daniel Ortega announced three days of national mourning on state television for his longtime ally Borge, who died Monday night at age 81 after being hospitalized last month for pneumonia and other ailments. Borge joined with Carlos Fonseca Amador and others in 1961 to found the Sandinista National Liberation Front. It was named for Augusto Cesar Sandino, who fought against U.S. military intervention in Nicaragua in the 1930s. Ortega joined the front later and became its leader.

“Like Carlos Fonseca, he (Borge) is one of the dead who never die,’’ first lady Rosario Murillo said in an emotional announcement, her voice appearing to break at times. “He will always be with us in the Sandinista Front.’’

Borge’s body, dressed in a faded olive drab military jacket, lay in state in an open casket at the National Palace of Culture. Ambassadors and government ministers filed by, some tearfully. A few mourners bowed or saluted in front of Borge’s body.