Nasa presidential candidate's chief agents stormed out of the national tallying centre at Bomas of Kenya on Friday evening.
The Nasa officials hinted that they may opt for mass protests to force the Independent Electoral and Boundaries Commission (IEBC) to declare Mr Raila Odinga as the winner of the Tuesday polls.
Nasa co-principal Musalia Mudavadi and Siaya Senator James Orengo accused the IEBC of disregarding their concerns and insisting on declaring President Uhuru Kenyatta as the winner of the presidential poll before addressing the concerns they raised over the transmissions of results.
"The issues we raised have not been adequately addressed and the commission (IEBC) telling us to put our concerns in writing was like a PR exercise," Mr Mudavadi said.
"For the record, we are storming out and we shall not be party to the games being played by the commission," Mr Orengo said, vowing as agents not to sign any documents as required by law.
They said the source of the conflict was the IEBC's meeting with agents of presidential candidates late Friday where the electoral agency informed the agents of its intention to declare President Uhuru bas the winner in the Tuesday polls.
Nasa had earlier in the day, during a meeting between the IEBC and its principals led by Mr Odinga, presented a five page document to the commission detailing anomalies in forms 34A and 34B they say compromised the results in favour of the incumbent.
During the meeting, the IEBC had asked the opposition coalition leaders to give it time to consider the concerns raised in the document that was also shared with diplomats and religious leaders on Friday.
However, around 6.30pm, the commission's Chief Executive, Ezra Chiloba summoned an urgent meeting of all the agents where the news of Mr Uhuru being declared the winner was delivered.
He assured the Nasa agents that the concerns raised will be dealt with after the announcement had been made.
Mr Orengo alleged that the IEBC had shown that it is an arm of the executive, considering the decisions it has been making lately.
The Siaya Senator-elect alleged that the President, his deputy and the entire government machinery knew all along what the electoral commission was going to do.
"All the blood and sweat of Kenyans to create an independent electoral commission has resulted to naught. That struggle took many people to jail, while some were killed in order to have this Constitution," Mr Orengo said.
"This is not a question of Kenya being greater. Kenya can be greater if it can take care of all of us. This is not the end of the matter," Mr Orengo insisted.
He ruled out going to the Supreme Court saying "judgment is now out there in the court of public opinion".
"I can tell you, Kenyans always rise up. The resilience of Kenyans to deal with impunity, to deal with violations of their rights every time those rights have been trampled upon they have always risen up," he said.
He added: "I would urge the Kenyan people to judge the decision of this commission (IEBC) in the contest of the Constitution that belongs to the people and not any individual."
"Going to court is not an alternative for us. We have been there before and everybody knows what we got. But the Kenyan people have never disappointed in standing up for their political rights," Mr Orengo.
Nasa further questioned the competence of the several people who have led the retinue of observer missions the IEBC invited to monitor the elections.
He said the missions should adopt a policy of vetting the individuals before deploying them to observer missions.
"The missions should vet observers to determine if they have relationships with the actors in the political contest. Some of them have interests that serve those in government," he said.
He named former Ghanaian President John Mahama, who is leading the Commonwealth observer mission, former South African President Thabo Mbeki, who is leading the AU mission and former US Secretary state John Kerry who is leading the joint US embassy and Carter Centre missions as examples.