The President, Mr John Dramani Mahama, has entered appearance in the petition instituted by the New Patriotic Party (NPP) at the Supreme Court challenging his being declared winner of the December 7, 2012 presidential election.The Electoral Commission (EC), which is also a party in the petition, entered appearance through its lawyers on Wednesday, while lawyers for President Mahama filed an appearance on his behalf yesterday.Ghana's biggest opposition party, the NPP, filed a petition challenging the results of the December 7-8, 2012 presidential election at the Supreme Court on December 28, 2012.The plaintiffs in the suit are the NPP's presidential candidate, Nana Addo Dankwa Akufo-Addo; his running mate, Dr Mahamudu Bawumia, and the National Chairman of the NPP, Mr Jake Obetsebi-Lamptey.One of the lawyers for the petitioners, Mr Godfred Yeboah Dame, confirmed receipt of the EC's conditional appearance to the Daily Graphic in Accra yesterday, while Mr Tony Lithur, a member of the NDC legal team, also established that the President entered appearance yesterday afternoon.According to Mr Dame, Lynes, Quashie-Idun and Co entered appearance on behalf of the EC and explained that the EC had seven days, as per the Supreme Court rules (CI 74), to file a defence.The President's legal team has indicated its readiness to defend him, arguing that claims by the petitioners were erroneous.According to the plaintiffs, irregularities recorded during the elections favoured the NDC, noting that 24,000 of the pink result sheets from some polling stations indicated that those irregularities were enough to affect the results.The Chairman of the EC, Dr Kwadwo Afari-Gyan, on December 9, 2012, declared President Mahama winner of the polls with 50.70 per cent of the votes cast, while his closest contender, Nana Akufo-Addo, placed second with 47.74 per cent.