LAGOS, Nigeria — Nigeria's electoral commission on Wednesday approved the creation of an opposition coalition that will join three political parties and is expected to present a strong challenge to President Goodluck Jonathan and his party in 2015 elections.

The commission announced that the parties met all statutory requirements for their merger into the All Progressives Congress that includes powerful Muslims from the north and equally influential Christian southerners.

Among them are former military ruler Gen. Muhammadu Buhari, a popular northerner who some consider a strong anti-corruption fighter. Jonathan is largely perceived as failing despite promises to halt the endemic graft that is debilitating to the economy of Africa's biggest oil producer.

The coalition's most powerful figure from the south is Bola Ahmed Tinubu, a former senator and past governor of Lagos State who is considered a kingmaker.

"All sorts of obstacles were thrown into our path by anti-democratic forces," said coalition spokesman Lai Mohammed, welcoming the decision. He said the coalition's emergence is "a victory for Nigeria and for democracy" that propels the country into "the league of top democratic nations with two major political parties."

Jonathan now is presented with the double challenge of a strong opposition and rifts within his own People's Democratic Party that could damage any bid to extend his presidency. Jonathan has not yet decided whether he will run, his office announced this week. He came to power by default as he was vice president when President Umar Yar'Adua died in 2010 and he then won the presidential election in 2011.

Northern politicians are opposed to Jonathan, a southerner and Christian, running for a second four-year term in 2015, objecting that northerners have been cheated of their chance at the presidency by Yar'Adua's death. While there is nothing in the constitution about it, there is an unwritten agreement in the ruling People's Democratic Party that power must be shared between the north and the south and a northern president should be succeeded by a southerner, to balance power in Africa's most populous nation. Nigeria has more than 160 million people, divided about equally between Muslims who dominate the north and Christians who live mainly in the south.

Traditional rivalries between Christians and Muslims have intensified because of an Islamic uprising in the northeast of the sprawling nation. The Boko Haram terrorist network is accused of the killings of more than 1,600 civilians since 2010, according to an AP count.

The People's Democratic Power has won every election since decades of military dictatorship ended in 1999 and democracy was restored.

Tinubu's support ensured Jonathan won the vote in the southwest in the 2011 elections, clinching the president's victory. Jonathan would have difficulty securing those votes without Tinubu's backing.

Jonathan is also confronted by a revolt within his own party, from some governors with presidential aspirations. In the most dramatic manifestation of the divisions, a handful of pro-Jonathan legislators who want to impeach Rivers State Gov. Rotimi Amaechi led thugs into the National Assembly and started a fight in which one legislator broke the mace — the symbol of authority of the house — beating up another legislator.

The new coalition is considered the first viable option to PDP rule. But it too faces challenges in deciding who to present as its presidential candidate. Buhari, who appears an obvious choice, is a strong contender in the north but likely would have difficulty garnering votes from Christian southerners, even with the support of the coalition's southern partner, Tinubu's Action Congress of Nigeria.

The coalition's statement promised "plans to turn today's hopelessness into a time of great opportunities, to reverse the downward slide in our socio-economic development, and to ensure that every Nigerian benefits from the commonwealth, instead of the present situation in which a few fat cats are milking the system dry at the expense of the citizenry."