On day one, several aspirants were forced to wait for hours at various IBEC stations as the commission started the verification and clearance exercise.
Others who have been cleared include National Assembly Deputy Speaker Moses Cheboi, Joel Ayieni, Former Naivasha MP John Mututho and Bahati MP Kimani Ngunjiri
Tolgos, who is exiting the governor seat after serving two terms, will battle for the Senate seat on Jubilee ticket against the incumbent Onesmus Kipchumba Murkomen of UDA.