Ghana’s former president John Mahama has scored a landslide primary victory to become the opposition candidate in the West African country’s 2020 elections.

Mahama was president from 2012 to 2016, when he lost a re-election bid to President Nana Akufo-Addo of the New Patriotic Party (NPP) over a faltering economy and corruption allegations.

“Tonight, I want to serve notice to Ghana that from the outcome of this election, the NDC is strong,” Mahama said after his victory was announced.

“The NDC is united. The NDC is poised for victory in 2020. And nothing, absolutely nothing, can stop our march towards Flagstaff House (the seat of government),” Mahama said at the social democratic party’s headquarters in Accra.

“It is a call to duty, a call to action and a call to battle. I wish that this fire will keep on burning… It is my hope that we will work together and eschew all attempts to divide us,” he said.

Ghana was one of Africa’s fastest growing economies in 2018, fuelled by a surge in oil and gas production. The former British colony is also a major producer of gold and cocoa.