Azimio leader Raila Odinga's planned countrywide protests on March 20 will coincide with opposition protests in at least four other African countries.
There are protests in Nigeria, Senegal, Tunisia and South Africa, marking a growing rebellion against sitting presidents.
The veteran opposition leader has called on his supporters to gather in Nairobi, on the day he has unlawfully declared a public holiday.
He will lead protests against President William Ruto's Kenya Kwanza administration and march to the State House to hand in a petition.
Raila is pushing the government to halt the recruitment of electoral commissioners, lower the cost of living and return subsidies on basic commodities.
In Nigeria's capital Lagos, opposition politicians have called for street protests over what they have described as rigging in last month's presidential elections.
Nigeria’s main opposition People’s Democratic Party (PDP) led by its presidential candidate Atiku Abubakar, is protesting in the streets over alleged electoral fraud.
On Monday, they marched to Nigeria’s Independent National Electoral Commission (INEC) offices, protesting against the country’s election results released a week ago.
Supporters, who caused traffic jams in parts of Abuja, also carried placards with inscriptions, "We say no to injustice and fraud" and "No more cheating”.
They converged at the main entrance of INEC headquarters but found the gates locked. They will return for a sit-in on March 20.
In Tunisia's capital Tunis, protests will be held on March 20 to pressure the government over the alleged authoritarian rule by President Kais Saied.
Thousands of opposition supporters including members of the Tunisian General Labour Union (UGTT) have been rallying in the capital Tunis.
The UGTT is one of the most powerful organisations in Tunisia and one of the few that can openly and effectively challenge government policies.
Protesters have slammed the government's crackdown on the opposition, including attempts to target the union itself.
In South Africa, EFF leader Julius Malema has threatened to unleash the “mother of all protests” which he said would bring South Africa to a standstill on March 20.
Malema said his party will not seek permission to hold the mass protest, and warned businesses to close shop on the day.
In Senegal, supporters of Senegalese opposition leader Ousmane Sonko are protesting in the capital Dakar in support of the aspiring presidential candidate, who faces a libel case set to resume this week.
The demonstrations are the latest expression of growing tensions in Senegal in the run-up to a 2024 election.
The opposition has warned President Macky Sall vie from running for a controversial third term, which critics say is unconstitutional.