The findings released on Monday by the Consortium of Researchers on Governance (CRG) places Dr Mutua at number 43 with a revenue collection of -16.7.
It listed Sonko at number 44 with a revenue collection of 7.9 per cent.
The survey ranks Mohammed Abdi (Wajir) Fahim Twaha (Lamu) and Homa Bay’s Cyprian Awiti as the worst-performing governors scoring 2.4 per cent, 10.12 per cent and 13. 47 per cent respectively.
It listed Kakamega Governor Wycliffe Oparanya as the best performing county boss at 87.23 percent followed by his Laikipia counterpart Ndiritu Muriithi at 84.12 per cent.
Tharaka Nithi’s Muthomi Njuki came in third with a score of 78.54 per cent while Makueni’s Kivutha Kibwana ranked fourth.
Embattled Kiambu boss Ferdinand Waititu, who is facing corruption charges, was placed at a respectable 11 with a source revenue of 57.7 per cent.
The firm’s data analyst Mc’Olonde said the survey measured source revenue growth for counties and their score in County Accountability Index.
He attributed Sonko’s dismal performance to the Auditor General’s report during the last financial year that gave Nairobi County a disclaimer opinion.
The CRG report contradicts that released by All Africa Advisors (AAA) last week that ranked Dr Mutua and Sonko as the best performing governors.
The survey ranked Kiambu Governor Ferdinard Waititu as the worst-performing governor followed by his Homabay counterpart Cyprian Waititu.
AAA said it measured county performance through indicators such as health, housing, safe water provision, governance, food security and investment and manufacturing.