Ghana's Supreme Court will decide whether to overturn the results of 2012 presidential polls on 29 August, the nine-judge panel said Wednesday.

In a case that has gripped the west African nation, the largest opposition party, the New Patriotic Party (NPP), is challenging President John Dramani Mahama's win last December.

The NPP has said the vote was marred by irregularities and that their candidate Nana Akufo-Addo was the true winner.

"The petition is adjourned to the 29th of August 2013 for judgement," Justice William Atuguba, the presiding judge, said at the close of a hearing on Wednesday.

Final arguments were heard on 7 August.

Ghana's electoral commission said Mahama earned 50.7 percent of the vote to Akufo-Addo's 47.7 percent. International observers generally praised the polls.

The NPP filed their case shortly after Mahama was declared the winner. Deliberations, which began in April, are broadcast live on television and radio, and have been closely watched in the nation of 25 million people.