By Claire Marshall
BBC News, Mexico City
The leader of Mexico's Zapatista rebels has spoken publicly for the first time in four years to criticise Mexico's political parties.
Marcos says Mexico's presidential candidates are "scoundrels"
Subcomandante Marcos said he would not be voting for any of the candidates in next year's elections, calling them "a bunch of shameless scoundrels".
He accused the leftist mayor of Mexico City, currently front-runner in the 2006 presidential race, of treason.
Andres Manuel Lopez Obrador was a false leftist and dishonest, he said.
The enigmatic head of the Zapatistas made his appearance - wearing his trademark black ski mask and smoking a pipe - at a meeting of activists near his jungle headquarters in southern Chiapas.
Marcos led the armed Zapatista uprising in 1994, when about 150 people were killed in clashes in Chiapas, Mexico's poorest state.
Their rebel group's fight for improved rights for Mexico's indigenous Indians has since been largely peaceful but has made relatively little progress.
Talks with the government collapsed in 2001 after a proposed Indian rights bill was watered down by Congress.
Marcos, who appears to be trying to boost the rebels' political influence ahead of the elections next July, is planning a tour around the country to unite workers and students around a leftist agenda.