Voi MP Jones Mlolwa cast his vote at Ghazi Primary School polling station in Voi, Taita Taveta county.
Mlolwa who is seeking a third term on a Jubilee ticket arrived at the station minutes to 6am.
He was the first person to cast the ballot.
The MP said he has confidence in the Independent Electoral and Boundaries Commission adding that the process was well conducted.
Mlolwa spoke to journalists outside the polling station.
"The exercise is well organised and we are confident that the polls body will do a good job," he said.
The legislator further asked his supporters to come out in large numbers and vote for him.
Mlolwa is facing competition from other five candidates who want to unseat him.
They are Albanus Muli (UDA), Vincent Masawi (ODM), Veronica Wakesho (ANC), Godfrey Mwanjulu (independent) and Wiper's Hamisi Chome.
(Edited by Bilha Makokha)
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