Nicaraguan President Daniel Ortega, a former Marxist guerrilla leader, looks likely to gain re-election after heavy social spending won him strong support among the country's poor.

Mr Ortega has overseen a period of economic progress in his five years in power, backed by financial aid from his socialist ally in Venezuela, Hugo Chavez.

A former commander of the Sandinista rebel army that won power in a 1979 revolution and a Cold War adversary of the United States, Mr Ortega has solidified his hold on the Central American country with programmes to improve health and education, micro-credits and gifts of livestock.

"He has helped the poor. Other presidents didn't do that," said 19-year-old law student Wendy Gonzalez after casting her vote in a poor area of the capital Managua.

Mr Ortega has a big poll lead over a conservative opposition whose two main candidates failed to unite against him.

He was able to run for re-election thanks to a 2009 ruling by the Supreme Court - which his Sandinista party controls - that did away with a ban on consecutive terms.

Backed by Venezuela, Mr Ortega has cut poverty in the largely agrarian nation, and is credited with allowing the private sector to operate freely.

A recent poll showed he was on course to win nearly half the votes in the election, well above what he would need to avoid a run-off vote.

However, Mr Ortega is also blamed for undermining democratic institutions and some critics fear he aims to stay in power indefinitely like Mr Chavez.

Mr Ortega led Sandinista rebels in ousting the Somoza family dictatorship in the 1979 revolution and was the top figure in a government that withstood a US-backed "Contra" rebellion throughout the 1980s.

First elected president in 1984, he was voted out in 1990.

He then spent 16 years as the main opposition leader before regaining power in a 2006 election.