Nairobi — A new survey by Trends for Insights Africa (TIFA) has placed Azimio La Umoja- One Kenya Coalition presidential candidate Raila Odinga as the most popular presidential candidate in Nairobi with an approval rating of 50 percent.

Odinga's rating is twice as much as that of United Democratic Alliance (UDA) presidential candidate William Ruto who came second at 25 percent.

In the findings, Roots Party presidential flag bearer George Wajackoyah had an approval rating of seven percent.

David Waihiga of Agano party polled in at fourth with an approval rating of one percent.

"632 respondents were interviewed spread across the 17 constituencies," the pollster said.

The former Prime Minister's popularity has grown from 41 percent which he had in May while Ruto's popularity has dropped. In May Ruto's approval rating in the County was 26 percent.

On political parties and alliances, ODM and Azimio La Umoja are both more popular than their rivals, UDA and the Kenya Kwanza Alliance.

The Odinga-led alliance is the most popular outfit with an approval rating of 46 percent and trailed by the Kenya Kwanza Alliance which has a rating of 24 percent.

Orange Democratic Movement (ODM) party enjoys a commanding lead with 30 percent while UDA has a rating of 22 percent.

Odinga and Ruto are considered to be the two main frontrunners in the hotly contested August polls.

The presidential contest which has been dubbed as a two horse race will see the close to over 22 million voters cast their ballot on who will be President Uhuru Kenyatta's successor.