Surprise candidate Peter Obi is the outsider in Nigerian politics

Former governor Peter Obi is the youngest of the three frontrunners in Nigeria's presidential race.

At 61, Peter Obi is the candidate for the Labour Party and is facing former Lagos governor Bola Ahmed Tinubu, running for the ruling All Progressives Congress (APC) and former vice president and sixth time hopeful Atiku Abubakar of the main opposition Peoples Democratic Party (PDP).

Contrary to his challengers, Peter Obi is a Christian from southern Nigeria, an Igbo-speaking region, and as served as Anambra state governor where he developed a reputation for frugality and integrity.

Obi's growing popularity and social media appeal are unprecedented in modern Nigeria and many younger voters, mostly in their 30s, see him as a departure from endemic corruption that has plagued Nigerian politics for decades.

Some opinion polls forecast an Obi victory but critics say his popularity is restricted to social media and among young Nigerians, many of whom don't have voter cards.

Former president Olusegun Obasanjo and his fellow Yoruba leader Ayo Adebanjo, have publicly endorsed Obi's bid, insisting it is the turn of the Igbo to get the presidency since other regions have had their chance at the top job.