ODM party leader Raila Odinga on Tuesday landed in Kilifi County as he positions himself to take on President Uhuru Kenyatta during the August polls.
Raila addressed several roadside rallies where he urged residents of the county to register in large numbers.
He said the only way through which the opposition can dethrone Uhuru from State House is by registering in large numbers and voting.
He was accompanied by Mombasa Governor Hassan Joho and Kilifi's Amason Kingi.
"Kilifi has upwards of 300,000 people with national identity cards who are yet to be registered as voters," Raila said.
"These people need to be fully enfranchised to participate in choosing leaders for our country. During the exercise, I once again found that my national identity card had been used to register somebody else as a voter."
"This is exactly the kind of mischief that we have been opposing in the run-up to the election. The IEBC register as it is needs a thorough biometric audit by a credible firm with a proven track record."
The opposition chief is on a countrywide tour popularising the opposition coalition ahead of the polls.