Presidential aspirants who lost to Atiku Abubakar in the Peoples Democratic Party primary have pledged to support him.
Mr Abubakar defeated 11 other aspirants at the opposition party's convention held in Port Harcourt, Rivers State on Saturday and Sunday.
The former vice president scored 1,532 votes, more than double that scored by his closest challenger, Aminu Tambuwal, who had 693 votes. Senate President Bukola Saraki came third with 317 votes.
Speaking on behalf of the other aspirants, Mr Saraki, at the venue of the convention, pledged to support Mr Abubakar.
"You truly deserve this," he told Mr Abubabakr.
"On behalf of al of us, we congratulate you."
Earlier Mr Abubakar had thanked his co-contestants and pledged to call on them in his efforts to help the party win the 2019 presidential election.
In response to that, Mr Saraki said "even if you don't call us, we are here to work with you."
The senate president took a jibe at "doubting Thomases" who suggested that the convention would lead to some of the presidential aspirants walking away from the party.
"We are all here," he said. "We are only working with you (Mr Abubakar) to victory."
After the convention, one of the presidential aspirants, Governor Ibrahim Dankwambo of Gombe State, also pledged to support Mr Abubakar.
"Congratulations to Former Vice President of Nigeria, His Excellency, Alhaji Atiku Abubakar on his emergence as the flag bearer of our great party, the People's Democratic Party. We are united under one Umbrella and we will work assiduously for our party's victory in 2019," Mr Dankwambo said on his Twitter handle.
Mr Dankwambo scored 111 votes at the convention. His spokesperson had earlier confirmed that the Twitter handle belongs to his principal.
Gombe State Governor, Ibrahim Dankwambo [Photo credit: The Worldfolio]
"I cannot do it alone," Mr Abubakar said in his acceptance speech. "I need your support, I need your understanding," he told his fellow aspirants.
It is not a one man's job, it is one of collective responsibly, he added.
He described the process that produced him candidate as free, fair and innovative.
Congratulations to Former Vice President of Nigeria, His Excellency, Alhaji Atiku Abubakar on his emergence as the flag bearer of our great party, the People's Democratic Party.
We are united under one Umbrella ☂ and we will work assiduously for our party's victory in 2019. pic.twitter.com/BsbzlDDbd1
- Governor Dankwambo (@HEDankwambo) October 7, 2018
"We have witnessed the most credible, transparent and fair primaries," the candidate said, adding that it is the most innovative process since the inception of PDP 1998.
He said the PDP and other political parties should learn from the process and improve upon it.
Mr Abubakar, who spoke without a prepared script, commended his challengers, saying they showed "a sense of unity, a sense of purpose and a sense of commitment."
2019: Atiku emerges PDP presidential candidate; to challenge Buhari
He described President Muhammadu Buhari as clueless, adding that the PDP cannot afford to fail at the general election.
Mr Abubakar is expected to be the main challenger to Mr Buhari in the 2019 presidential election. The president has already been declared the APC candidate for the election.