Voters in the rural Tain constituency of western central Ghana were trickling into polling stations Friday in an election that could decide who becomes the country's next president.

The African Elections Project (AEP) reported from Accra that the ruling National Patriotic Party (NPP), which lost the recent parliamentary election in the constituency, was boycotting Friday's vote.

Tain is the last of Ghana's 230 constituencies to vote in a presidential run-off election. After polling in the other 229 constituencies last Sunday, John Atta Mills of the National Democratic Congress (NDC) had a lead of 23,055 votes over the NPP's Nana Akufo-Addo.

The electoral commission said after Sunday's voting  that the national result was so close that the Tain result could determine the outcome, and declined to declare a winner before the constituency had voted. The election in Tain was delayed by problems with ballot papers.

The AEP reports that NPP supporters demonstrated in Tain on Thursday, calling for the cancellation of Friday's voting. It also reported  that the NPP tried on Thursday to get a court in Accra to issue an injunction preventing the electoral commission from announcing the result of the presidential election. But the judge ordered that the party needed to give notice of its action to the commission and the NDC.

The Tain constituency is in the Brong Ahafo region of Ghana. It is  reported to have  53,880 voters. On December 7, the NDC's parliamentary candidate received 16,211 votes, while the NPP's won 14,935 votes.

Atta Mills and Akufo-Addo were forced into a run-off when neither received 50 percent of votes in the first round of the presidential elections on December 7. Atta Mills, who was vice-president to former ruler Jerry Rawlings, unsuccessfully contested Ghana's last two elections against the outgoing president, John Kufuor.