Ghana’s main opposition party on Thursday said it had a strong lead in elections and called on President John Mahama to concede defeat, while comments dismissed as “treasonable” by the incumbent’s campaign team.

The New Patriotic Party said its candidate, Nana Akufo-Addo, had won 52 per cent of the vote according to its own tally of Wednesday’s presidential poll, against 44.8 per cent for Mahama.

The Electoral Commission said it had not certified any results in the closely fought race to lead the West African nation that has seen a series of peaceful transfers of power.

However, figures shown by television and radio stations showed the opposition making gains in both races.

“These are results that were declared at the polling stations. I am calling on the president to concede defeat,’’ NPP campaign chief Peter Mac Manu said.

A senior official for the ruling party, Samuel Ofosu-Ampofo, countered that Mahama was “comfortably ahead” and asked his supporters to remain calm.

“The results are still trickling in and the call and declaration by the NPP is irresponsible and treasonable because it can throw this country into chaos,’’ he added.

Ghana is one of Africa’s most stable democracies and voters have rejected the government of the day twice since 2000.

Until 2014, the country also had one of Africa’s most dynamic economies, though growth has slowed in part due to a fall in the price of its commodity exports.