Two of Nigeria's most prominent opposition figures have announced they have switched parties in a dramatic political realignment ahead of next year's presidential election.

Peter Obi and Rabiu Kwankwaso, who finished third and fourth respectively in the 2023 presidential race, have both joined the Nigeria Democratic Congress (NDC), raising the prospect of a joint ticket to challenge President Bola Tinubu.

They were previously in the African Democratic Congress (ADC), along with former Vice-President Atiku Abubakar, who came second in the last election.

While this could be seen as a fragmentation of the opposition, supporters of Obi and Kwankwaso say it will give their alliance greater focus.

Both men are former governors and command significant grassroots followings.

Obi is hugely popular among young voters across the south, while Kwankwaso wields considerable influence in the north.

The move comes just nine months after Obi, Kwankwaso and Abubakar joined the ADC but that alliance quickly became mired in legal battles over party leadership - something Obi blamed on the government.

"The same Nigerian state and its agents that created unnecessary crises and hostility within the Labour Party that forced me to leave now appear to be finding their way into the ADC," Obi said on Sunday.

He was the Labour Party candidate in the 2023 election.

Allies of President Tinubu have denied that they have been trying to sabotage opposition parties.

Obi and Kwankwaso were formally received at the NDC's national headquarters in Abuja by the party's national leader, Senator Seriake Dickson, on Sunday.

Speaking afterwards, both men called for national unity, greater opportunities for young people, and an end to the infighting that has plagued Nigeria's opposition.

Political analyst Bala Yusuf told the BBC the move could reshape Nigeria's electoral landscape.

"If the NDC fields Obi as its presidential candidate and Kwankwaso as vice-president, they will definitely give the ruling APC a run for their money at the polls," he said.

They have not yet said who the presidential candidate will be - an issue that has broken up several previous Nigerian political alliances.

President Tinubu, who took office in May 2023, has not yet publicly commented on the opposition's latest manoeuvres.

Elections are scheduled for early January next year -they will be the country’s eighth since the end of military rule in 1999.