Voters in the Dominican Republic are going to the polls on Sunday to choose a new president, in a tight race between two rivals.

Polls show 60-year-old Danilo Medina, of the ruling Dominican Liberation Party (PLD) is leading by a comfortable margin of five to ten percentage points over 70-year-old Hipolito Mejia, who is hoping to return to power for the opposition Dominican Revolutionary Party (PRD), eight years after a failed re-election bid, having been president from 2000 to 2004.

President Leonel Fernandez is constitutionally barred from seeking a third term.

Four other candidates are also running, but opinion polls say they have marginal support and no realistic chance of winning.

Medina is promising to boost economic growth in the Caribbean country.

Mejia has vowed to fight corruption and create jobs - but his critics point out that when he finished his first presidential term, the country was facing probably the most serious financial crisis in its history.

While the Dominican Republic is far wealthier than Haiti, its poor neighbour on the island of Hispaniola, many Dominicans still struggle to meet their basic needs, prompting some to seek a better life by slipping in to nearby Puerto Rico, a US territory.

Many Dominicans blame poor Haitian immigrants for taking their jobs and getting involved in crime, which has doubled in the past decade.

The Dominican Republic is a popular resort spot, famous for its white sandy beaches and golf courses, but it also is the leading Caribbean trans-shipment point for South American drugs, destined for the United States and Europe.

About five per cent of the nation's 6.5 million eligible voters live overseas, including 220,000 registered in New York state.

A run-off will be held next month if no candidate manages to get at least 50 per cent of the poll.