• Kenya Kwanza's William Ruto is second with 44.4 per cent.
• Waihiga Mwaure of Agano party is last with 0.1 per cent.
Azimio la Umoja presidential candidate Raila Odinga remains the most preferred presidential candidate, Tifa Research has said.
In poll results released on Friday, Raila is ahead with 46.7 per cent, while Kenya Kwanza's William Ruto is second with 44.4 per cent.
Roots Party's George Wajackoyah comes in third place with 1.8 per cent.
Waihiga Mwaure of Agano party is last with 0.1 per cent.
Tifa noted that support for Raila has increased across all nine regions except for the Central Rift region, from their last survey.
"Compared to the results from Tifa's June survey, the distribution of expressed voting intentions for Odinga has changed somewhat across the country in that he has gained in all the nine zones apart from Central Rift (-5%), his biggest gains being in South Rift, Nyanza, Western and Lower Eastern. (+15%, 13%, +13 and +12% respectively)" Tifa said.
Support for Ruto since Tifa’s last survey in June has also increased in six of the nine zones, especially in his ‘home’ turf.
"Over the last two years, DP Ruto’s presidential candidate popularity has remained within a very narrow range."
The survey said the proportion of undecided has gone down, which it attributed to the face to face method of collecting data.
No new opinion poll can be published less than five days to election, according to the law.
The last day therefore for any opinion poll to be published will be on August 4.
"It will be a very close election and voter turn out might make all the difference," lead researcher Tom Wolf said.
The poll had +/- 2.16 margin of error
The survey conducted between July 21 to July 26 where 2,056 respondents were across 9 regions across the country.
The regions include Central Rift, Coast, Lower Eastern, Mt Kenya, Nairobi, Northern , Nyanza, South Rift and Western.
The data was collected using face to face interviews at households.