ODM leader Raila Odinga is expected to join more than 1,000 delegates at a Building Bridges Initiative (BBI) consultative forum in Narok County on Friday.
Sources privy to the planning said the former Prime Minister will meet representatives from six Maa communities at Maasai Mara University.
The delegates are expected to discuss the BBI report in order to come up with a proposal suitable for the region.
The gathering is the curtain raiser for the BBI rally that will take place at Ole Ntimama Stadium on Saturday.
Host Governor Samuel Tunai said the county was ready to host delegates from Kajiado, Samburu, Laikipia, Isiolo, and Baringo to chart the way forward for the Maasai.
The multi-sectoral stakeholders' engagement will also bring together governors, senators, MPs, MCAs, elders, clerics, opinion leaders, women and youth representatives, business leaders, small scale traders and professionals .
"I welcome all delegates from our sister counties to Narok. We are ready ... we will engage each other and come up with proposals that will drive our counties and the country at large forward," Governor Tunai told a gathering of more than 1200 youths at the African Hope Social Hall on Thursday evening.
"We will join the rest of Kenya in making changes that will put this country on the path to cohesion and integration."
The youths promised to turn up in large numbers for the rally and support leaders across the political divide.
They said Narok will make history by observing inclusivity and not blocking anybody from the meeting.
"There will not be ugly scenes as witnessed at the BBI rallies in other counties. Youths of Narok embrace inclusivity. Let all leaders come on Saturday ... they are welcome," said Joseph Partoip, Narok's BBI youth coordinator.
The Narok rally will be the fifth in a series of consultative meetings that have taken place in Kisii, Kakamega, Mombasa and Kitui so far.
The meetings seek to validate the BBI report released in November 2019 by a 14-member team taskforce chaired by Garissa Senator Yusuf Haji.
Kajiado Governor Joseph ole Lenku, the BBI coordinator for Maa counties, hinted at focus on historical injustices, saying leaders will "put forth our own issues because every region has different concerns". Mr Tunai also said so.
Governor Ole Lenku noted that counties in the region share aspirations and trade partners hence the need for citizen participation on fundamental issues.
"All stakeholders in the counties ought to be given an opportunity to comprehend and discuss recommendations in the report," he said.
"The BBI engagement shall ensure the country achieves lasting peace, citizen participation, inclusivity and nationhood."
Narok MP Moitalel ole Kenta said President Uhuru Kenyatta and Mr Odinga should continue agitating for peace, unity, economic empowerment, political stability and inclusivity.
Mr Kenta, whose constituency will host the rally, asked the Maa community to wait for leaders' announcements come Saturday.
"Leaders, irrespective of their political persuasions, should put the country first and advance national values and principles as envisaged in the Constitution," he said.
"The public should join us in supporting the recommendations as we enrich the document by giving our views constructively for the good of this country."