Voters in the Caribbean nation of St. Vincent and the Grenadines decide Wednesday whether to break their ties with Britain's monarchy, even as Queen Elizabeth makes a rare visit to the region.

A two-thirds majority in the referendum is needed to adopt a proposed constitution that would replace the charter in place since independence from Britain in 1979.

If the charter is approved, St. Vincent and the Grenadines would join other Caribbean nations that have enacted new constitutions in recent months, including the Dominican Republic and the Cayman Islands.

The proposed constitution would remove the British monarch as the head of state and create a president nominated by the two political parties. Among other changes, it would establish a new court of appeals to replace Britain's Privy Council, which is now the highest court of appeal for the island nation.

Both the governing Unity Labour Party and the opposition agree the islands should become a republic. But members of the opposition New Democratic Party are encouraging voters to reject the charter because they say it does not sufficiently reduce the powers of the prime minister, and they want the president to be elected by voters, not selected by Parliament.

The country would remain a member of the Commonwealth, the organization of Britain and its former colonies.

Queen Elizabeth, who visited Bermuda on Tuesday, is in the region to attend a Commonwealth summit in Trinidad on Thursday.

Elections supervisor Sylvia Findlay told local media there are 97,000 registered voters, but the list contains an undetermined number of people who have died or moved away.

Monitors from the 15-nation Caribbean Community trade bloc, the Organization of American States and the Organization of Eastern Caribbean States planned to observe the referendum.