Anger and dissatisfaction on Monday met the census results in Central and North Rift regions, with many leaders questioning their authenticity.
The leaders said the figures released by the Kenya National Bureau of Statistics (KNBS) were incorrect.
Meru Governor Kiraitu Murungi protested the 1.5 million population for his county and said he will sue the bureau if corrections are not made.
Mr Murungi alleged that most of the people in Ngare Mara special ward were enumerated as being in Isiolo County but said they were promised a correction before announcement of the final tally.
“We even alerted the county commissioner (Allan Machari) who wrote to KNBS. We were told the mistake would be rectified so we cannot accept the 1.5 million as the actual population of Meru County. If they don’t correct it we will go to court,” Mr Murungi said.
In Nyeri, Governor Mutahi Kahiga said he was disappointed with the results that showed the county has a population of 759,164. He said he a figure of at least 850,000.
Turkana Woman Representative Joyce Emanikor said the county's recorded population of 926,976 is incorrect.
Ms Emanikor said Turkana North Constituency, the largest constituency with two wards, was "treated unfairly".
"The results can’t be as stated. We need to see the populations of villages such as Lorumoru and Kaemosea, among other unreachable areas."
Turkana Speaker Ekitela Lokaale said that generally, the census figures do not represent the reality of the county's demographic.