The National Super Alliance coalition is in a crisis after affiliate partners accused Raila Odinga of meeting President Uhuru Kenyatta on Friday last week without consultation or approval.
In what appears to be implementation of the pact between the two leaders, NASA steering committee chairman David Ndii said the decision was reached following a request by president Kenyatta and Mr. Odinga.
A source close to the opposition leaders, who sought anonymity because of the sensitivity of the matter, said Mr Musyoka, Mr Wetang'ula and Amani National Congress leader Musalia Mudavadi had formed a penchant for taking sides and opposing every opinion that Mr Odinga presented during meetings, much to the chagrin of the ODM leader.
"We take this opportunity to caution those opportunistic mindsets that will always wish to ride on confusion and unnecessary tribulations of our people as a country, " said Mr Okumu.
"It is as if only they know where the door to Jubilee house is".
These comments have cast a dark cloud over Monday's meeting.
The People's Assembly was launched by Odinga previous year after he disputed the 2 presidential elections held in August and October 2017.
It remains to be seen whether the high-stakes Athi River meeting will calm the political storm surrounding the NASA coalition.
Mr. Mahama, alongside other observer groups, had declared the August 8, 2017 elections which the incumbent Uhuru Kenyatta won, as free and fair, despite the irregularities alleged by Kenya's opposition leader, Raila Odinga.
"It's true our security has been restored", Junet said.
But Mr Odinga defended his move, saying it was the best option given the challenges facing the Opposition in recent days. "Stoking and threatening violence are not acceptable, nor are extra-Constitutional measures to seize power", they said, apparently referring to Mr Odinga's "People's President" push.
ODM has the majority of ward representatives from Nasa affiliate parties.
"I will not be surprised if some people abandoned the journey".