"There is not a lot left of the revolution we led back in 1979," Sandinista veteran Jonathan Antonio, who now cleans streets in the capital, was reported by the AFP news agency as saying.

He said "individualism, selfishness and cronyism" were now part of the government, since its second return to office in 2007.

Some of Ortega's allies in the region were expected to attend the celebrations, including Hugo Chavez, Venezuela's president, who has been Ortega's key ally since January 2007.

Chavez's government last year alone gave impoverished Nicaragua $457m in aid.