Deputy President William Ruto's opposition to constitutional changes suffered a backlash on Saturday after ODM, ANC and KANU parties endorsed the changes.
While the proposal is yet to be made public, it is believed that the country will go to a referendum to chose between presidential system and parliamentary system of governance.
"We cannot do things same way all the time. We must change the constitution for inclusiveness," Raila told ODM delegates on Tuesday as he pushed for reintroduction of the PM post.
While addressing the media on Friday, ANC leader Musalia Mudavadi said constitutional amendment was inevitable, days after secretly meeting with Raila in Kisumu.
And the calls garnered momentum in Samburu on Saturday after respective Secretary Generals of the aforementioned parties Edwin Sifuna, Godfrey Osotsi and Nick Salat said the country must go for a referendum.
"If the presidential system is the problem, we must change it. We must look for a way of accommodating even the minorities," said Salat in a statement that was supported by his colleagues.
Throughout his tours across the country, Ruto has openly opposed constitutional changes arguing that the country is not ready for another period of politicking.
Understandably, Raila is said to have agreed with president Uhuru Kenyatta to push for the fundamental changes in the constitution including introduction of three-tier government before their exit in 2022.