(CNN) -- Daniel Ortega is set to mark his third term as Nicaragua's president during an inauguration ceremony on Tuesday -- an event both buoyed by his pledges of moderation and marred by months of discord over voter irregularities.
Since the country's November elections, Ortega, 66, has reached for the political middle, making overtures to the business class with promises of encouraging foreign investment.
But his critics say they fear the former leftist revolutionary is looking to solidify Sandinista party control over state institutions and have pointed to reports of ballot fraud and voter intimidation.
According to a report presented by the Organization of American States, irregularities included problems providing identification card to vote, problems in the accreditation of observers and imbalances in political parties present at polling stations.
Ortega, who fought against the U.S.-backed Contras during the 1980s, won the country's elections in November with 64% of the vote, though subsequent protests and clashes have left several people dead.
Nicaragua's constitution bars presidents from being re-elected, but that did not stop Ortega from running in his sixth straight presidential race.
Ortega was first elected as president in 1985, and ran unsuccessfully in 1990, 1996 and 2001 before being elected again in 2006.
He is known as a Venezuela ally, had been a public supporter of former Libyan leader Moammar Gadhafi and remains a stalwart U.S. critic.
Tuesday's ceremony is also expected to draw other leaders who've historically bucked American interests in the region.
Iranian President Mahmoud Ahmadinejad and Venezuelan President Hugo Chavez, among other regional leaders, are scheduled to be on hand for the event.