Before proceeding to Jaramogi Oginga Foundation grounds on Saturday, ODM leader Raila Odinga held a close-door meeting with Governors Charity Ngilu and Alfred Mutua.
The two, who represent Kitui and Machakos respectively, have been critical of former Vice President Kalonzo Musyoka, who is struggling to regain his Ukambani backyard.
A source privy to the meeting at Capitol Hill offices said Mr Odinga lobbied for parliamentary system which he believes will solve some power wrangles in the country.
The source, who spoke in confidence, adds that the three also agreed to strengthen their parties at the grassroot ahead of future alliances.
"They held robust discussions on the referendum. Mzee explained to him why he wants Parliamentary system. He asked them to support it for the sake of amalgamation," he said.
"They all agreed to revamp their parties at grassroots to strengthen the parties for future coalitions," he added.
Raila has previously worked with Ngilu and Musyoka. Ngilu is the leader of Narc while Mutua, a second term governor, is the leader of Maendeleo Chap Chap.
“We are here because we want Uhuru and Raila to show us the way in 2022 and nobody will come between them,” Mrs Ngilu while addressing Kamba community.
“Raila has done a lot for this country and he is the only person who will fight for the people of Kenya.”
In his speech, Mutua also seemed to back party democracy, an indication that he's ready for a Parliamentary system of government.
“My party will consult with ODM on how we will field candidates in the 2022 General Election so that we get the numbers to change this country,” he said.
Raila's spokesman Dennis Onyango also seemed to confirm looming alliance, arguing that other parties are keen to work with ODM ahead of historic changes.
"Parties and leaders gravitating to ODM in Kibra is a case of history taking a turn; not an appeal for reinforcement as @WilliamsRuto sees it. Whenever history takes a turn, it leaves some stranded on the path it is turning from, who will always insist history is still with them," he said.
On Saturday, ODM Secretary-General Edwin Sifuna repeated his earlier assertion that Nasa may be buried after the Kibra by-election.
“We have said this before, we are counting our friends in Kibra. New alliances will be forged from this by-election,” Mr Sifuna told the Sunday Nation.