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.