Former Mungiki leader Maina Njenga has been cleared by Independent Electoral and Boundaries Commission to vie for the Laikipia senatorial seat on a Kanu ticket.
Mr Njenga was the first to be issued with a certificate in Laikipia.
Four other candidates were scheduled to present their papers yesterday with the rest expected today.
Meanwhile, an ODM senatorial candidate in Mandera failed to be cleared after it was discovered that both his proposer and seconder were not registered members of the sponsoring party.
Abdinasir Mohamed Khalif expressed his disappointment with the electoral body for not notifying him of the mishap early enough despite having submitted the names a day before clearance commenced.
“I gave out the names on Saturday and no official raised any objection until I came in to be cleared,” Mr Khalif said.
In Nyeri, the youngest Senate aspirant in the country Steve Maina Nderi was cleared to vie on New Democrats Party.
Mr Nderi, 22, will battle it out with former Mathira MP Ephraim Maina of Jubilee Party and independent candidates Paul Kanja, Wambugu Nyamu and Daniel Wamahiu.
In Embu, independent candidates complained over delay in manual verification of list of supporters, saying they were spending lengthy time pursuing clearance.
Led by Senate candidate Alex Mundigi, they appealed to IEBC to automate the process.
He said he arrived at the Tana Water Services offices at 8am and was only cleared at 4pm since the officials had to manually verify the list of 2,000 individuals.
Former Runyenjes MP Njeru Kathangu and his Manyatta MP Njeru Ndwiga who are seeking the same seat on Ford Asili and Jubilee Party tickets, respectively.
In Isiolo, five out nine senatorial candidates were cleared to vie for the seat.
Those cleared include Nominated Senator Fatuma Dhullo of Party for Reforms and Development, Ken Mutuma of the Empowerment and Liberation Party (ELP) and Molu Huka (PNU).
Reporting by Manase Otsialo, Joseph Wangui, Charles Wanyoro, Vivian Jebet and Alex Njeru