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.
However, Mr Kahiga said there was "some credibility" compared to the last census in 2009, which was marred by claims of the doctoring of figures.
“Our minds are still fresh with the manipulation that occurred then," he said.
But he added, "Anyone disputing the results should provide alternative scientific data and corresponding evidence of the same."
Earlier, Tharaka-Nithi Governor Muthomi Njuki and Tharaka MP Gitonga Murugara vowed to go to court to dispute the results, which indicated that the county has 393,177 people.
Governor Njuki and Mr Murugara led other county leaders in dismissing the figure and said they will petition the KNBS for a review or repeat of the exercise.
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.
In Baringo, Bartabwa MCA Reuben Chepsongol said the enumeration carried out in September was a scam and that the results were incorrect.
Baringo was found to have a population of 666,763, with Tiaty leading with 153,353.
“We are very sure that in Baringo there are more than 600,000 people, contrary to what is purported by the national bureau of statistics. The process was flawed and most of the people from our region were counted elsewhere. This will be to our disadvantage when it comes to funding," Mr Chepsongol said.
Some leaders however, welcomed the results.
In Baringo, some welcomed the census report saying they will now have a say on the choice of the next governor.
An elated Tiaty MP William Kamket said, “We shall never again play second fiddle. We shall have a bigger role in the election."
In Uasin Gishu County, Amani National Congress (ANC) Chairman Saina Nechu remained positive despite pointing out that the exercise was marred by irregularities.
He said, “Despite the fact that some people were left out, the census report gives a good direction and rough estimates of what people should expect in 2022."
Huruma Ward MCA Peter Chomba said he was satisfied with the exercise and the results for Uasin Gishu.
“My only concern is the high population recorded from North Eastern counties. Where did all those numbers come from?”
In Kirinyaga, Governor Anne Waiguru lauded the bureau for releasing the data early and without a back-and-forth as it was the case in 2009.
“The data should be looked at in light of issues affecting the country and those that we expect the Building Bridges Initiative (BBI) taskforce to address in its report,” said Ms Waiguru.
She said it she expects the data to be used to address the public wage bill, change of the country’s governance structure, delimitation of electoral units, review of boundaries and the public outcry on over representation.
“I also wanted high numbers in Kirinyaga but I am comfortable. The 2009 data was not credible and cannot be a benchmark for the current one,” the former Devolution Cabinet Secretary told her colleagues in North Eastern.
Nandi Senator Samson Cherargei called on residents to desist from family planning and sire more children in the county that has 800,000 people.
Senator Cherargei said resources will only be allocated as per the population.
“It is a challenge ... We need to seriously give birth. We call on our men to be going back home early," he said.
"We call on our women to also offer a conducive environment for men. Let’s not put them under a lot of pressure so that they go back home early."
Samburu acting Governor Julius Leseeto said the census did not take into account pastoralists who were moving to Laikipia and Nyeri in search of pasture.
In Laikipia County, whose population was listed as 518,560, Governor Ndiritu Muriithi, said, “I would prefer to analyse the numbers before commenting but the figures seem to be in line with our estimates, based on records of births and deaths,” said Mr Muriithi.
However, he observed that the data should lead to creation of extra parliamentary electoral units in his county.
Resident Simon Mwangi said most people work in neighbouring counties so they could have been counted there.
In Bungoma, Maraka Ward Representative Ali Machani said they expected the government agency to release the results at former provincial level.
“We also expected to get results from the wards so as to start planning for 2022 General elections,” said Mr Machani, an MCA in the Bungoma County Assembly.
In Nyamira, Governor John Nyagarama disputed the census figure showing that the population increased from 598,252 to 605, 576 in the last 10 years.
“The census data is shocking since we have recorded a tremendous increase in the number of births in the last 10 years, compared to deaths. We will study the report and n share our feedback with the census team,” he said.
Meanwhile, analysis showed that Mandera County is the only administrative unit that registered a decrease in population while Nyamira County recorded the smallest increase in the last 10 years.
According to the 2019 Kenya Population and Housing Census report, the population of Mandera fell from 1,025, 756 in 2009 to 867,457 this year.
Other counties which recorded low population increases are Tharaka-Nithi (27,847), Vihiga (35,391), Bungoma (39,636), Nyandarua (42,021), Lamu (42,381), Taita-Taveta (56,014) and Nyeri (65,606).
Counties that recorded the highest population growth were Nairobi, with 1,258,704. Kiambu (794, 453), Nakuru (558,877), Kajiado (430,528), Busia (405, 606), Kilifi (344,348), Machakos (323,348), Narok (306,953), Uasin Gishu (269,007) and Mombasa (268,963).
Reports by Sammy Lutta, Flora Koech, Dennis Lubanga, Wycliffe Kipsang, Joseph Wangui and Gitonga Marete