ODM leader Raila Odinga shared a late-night message with his supporters asking them to fight oppressive regimes as they have done in the past.
Raila said Monday's demo is not about personalities, tribes, or race but about the interest of the country.
He said he is interested in ensuring that Kenyans are happy at whatever cost reiterating that Kenyans should turn out in large numbers for Monday's demo.
"My dear Kenyans, I'm not interested in your tribe, your race, your religion, your age. I am only interested in your happiness. We make possible the impossible. We are Kenyans. We set the trend," Raila said.
"I call on our people to awaken the old fighting spirit that was always capable of bringing down failed bloodthirsty regimes. People who want to take charge of their destiny can do it despite threats and intimidation. In a matter of hours, we begin taking over our country and our destiny."
Raila announced he and his supporters to will hold demos on Monday during which they will march to State House.
The former PM had said the march to the State House will be to reclaim their victory.
"We will hand over our petition to the President wherever he will be, but peacefully… If he will be at State House, only two or three people will walk into State House to go and present the petition," he said on Saturday.
Raila is expected to meet with his supporters at the Central Business District ahead of the start of the demonstrations.