Tain is set to decide the cliff-hanger presidential race
Voting is under way in a remote Ghana district to decide the outcome of a knife-edge presidential election, despite a governing party boycott.
The New Patriotic Front (NPP) has sought an injunction to delay Friday's voting in Tain constituency, but the court adjourned the case until Monday.
NPP officials said the atmosphere in the rural district was not conducive to a free and fair election.
Tain did not vote last Sunday because of a problem distributing ballots.
Opposition candidate John Atta Mills has a narrow lead over the ruling party's Nana Akufo-Addo.
There is growing pressure on the governing party to accept the outcome of the election and to avoid stalling the process via the courts, say the BBC's Will Ross, in Ghana's capital Accra.
Amid heightened fears of poll-related violence, President John Kufour has again spoken out to urge both candidates to accept the election result, appealing to them to avert a constitutional crisis.
President Kufour is stepping down after serving the maximum two terms in office and his successor is due to be sworn in on 7 January.
Soldiers and police have been deployed across Tain - the last of Ghana's 230 constituencies to vote - and polling stations are due to close at 1700 GMT.
The electoral commission is not expected to announce the outcome from the district, along with the presidential result, until Saturday at the earliest.
Ghana state radio reported that NPP agents with loudhailers had toured towns and villages in the district on Thursday night urging supporters to boycott the vote. The party's attempts to block the ballot have been criticised by civil groups.
"We are trying to stop the election because we think the security situation on the ground is not conducive for a free and fair election," NPP spokesman Arthur Kennedy told AFP news agency.
Our correspondent says Mr Akufo-Addo cannot realistically win enough support among Tain's 53,000 eligible voters to overturn the lead held by Mr Atta Mills of the National Democratic Congress (NDC).
Mr Atta Mills won the area in the first round of voting on 7 December and the NDC is confident of victory.
RIVALS AT A GLANCE
JOHN ATTA MILLS (left)
Party: National Democratic Congress
Executive posts: Vice-president 1997-2000
Profession: University professor
Hobbies: Hockey, swimming
Family: Married with one child
NANA AKUFO-ADDO (right)
Party: New Patriotic Party
Executive posts: Attorney general 2001-03; foreign affairs minister 2003-07
Family: Married with five children
He has 50.13% of the approximately nine million votes already cast, compared with 49.87% for Mr Akufo-Addo.
Just over 23,000 votes separate the two candidates.
Mr Akufo-Addo won the first round in the national result but not by enough to avoid the run-off.
Officials from the NPP have been meeting and election observers suggest the party is now split on whether Mr Akufo-Addo should accept defeat, says our correspondent.
The West African body Ecowas has expressed deep concern over the escalating tension in Ghana.
The body's president, Mohammed Ibn Chambas, told the BBC that in the interests of the country the candidate with the least votes should concede by the end of Friday.
He said: "I believe that there comes the moment when each politician and each political party should place the supreme interest in the country to keep the stability of the country over and above their own interests.''
The NPP has said it wants a re-run of voting in a number of constituencies in the Volta region, claiming their polling agents were victims of brutality and intimidation in last Sunday's poll.
The NDC in turn complained of alleged intimidation and vote-rigging in the Ashanti region.
The electoral commission had said it would investigate those claims if provided with evidence.
Ghana is one of Africa's most stable democracies but stakes have been raised in this election - the fifth since the country's return to democracy in 1992 - by the discovery of oil off the coast.
Monitors hope the poll can help salvage the tarnished image of constitutional democracy in Africa, after flawed elections in Kenya and Zimbabwe, and military coups in Mauritania in August and in Guinea last month.