ODM leader Raila Odinga is among presidential aspirants who were Sunday cleared by the Independent Electoral and Boundaries Commission to vie for presidency.
Raila, accompanied by running mate Kalonzo Musyoka and NASA co-principals, presented his papers to IEBC at the Kenyatta International Connection Centre.
The National Super Alliance (NASA) then headed for a rally at Jacaranda Grounds in Nairobi as the official campaign period kicks off.
Other candidates who were cleared on Sunday include Ekuru Aukot of Third Way Alliance.
Abduba Dida of Alliance for Real Change had been turned back by IEBC officials for failure to have his papers certified. He was later handed his certificate by the elections agency after presenting his documents, duly certified.
The candidates have been asked to submit their campaign schedules with IEBC for harmonisation.