Mombasa Governor Hassan Joho has vowed not to submit to President Uhuru Kenyatta.
This comes days after Kenya Revenue Authority wrote to Diamond Trust Bank (DTB) seeking details of Mr Joho's bank account.
Joho has suggested that KRA is acting on the President's order.
The KRA letter to DTB was written on March 14, about 24 hours after an altercation between Uhuru and Joho when the President vowed to teach the vocal governor "a lesson".
Yesterday Joho, who was accompanied by Kilifi Governor Amason Kingi and Governor John Mruttu of Taita Taveta, stepped up his criticism of Uhuru's administration, describing Jubilee as a despotic regime that had sunk billions of shillings into a phantom irrigation scheme in the region.
On Saturday, the governors addressed a rally at Mkunguni Square in Lamu island where Joho suggested that the President was behind KRA's demand.
Reports indicate KRA has written to several commercial banks demanding information about Joho's bank accounts, including movement of cash.
The demand letter to DTB came a day after the explosive drama in Mombasa where Joho was barred from attending a presidential function in his county.
"In accordance with the powers conferred upon me by the above-quoted statutes, you are hereby given notice to provide bank statements, account opening documents, mandate forms and any other records for all accounts," Justus Kiuvu writes in the letter to DTB.
He wrote on behalf of David Yego, who is the commissioner, Investigation and Enforcement Department of the KRA.
"Kindly treat the matter as urgent," Kiuvu's letter reads further, stating that the details demanded related to account number 0038342001.
The bank is required to provide the statements dating back to January 2011, when Joho was serving as the Member of Parliament for Kisauni Constituency in Mombasa.
On Saturday, Joho said he was aware of the letter to DTB.
"KRA has written a letter to my bank. They want to know how much money I have, where I got it from and from which year," he said.
"I tell Honourable Uhuru Kenyatta [that] I have three bank accounts, one at Barclays (Bank), another at Stanbic (Bank) and another one at DTB. I give you the permission to take all that money to the last coin but I will not submit to you," he added.
Joho said he is ready to face an open and transparent probe and added that the KRA letter is linked to his criticism of the President.
Joho's troubles with KRA are however not new. The Johos are a wealthy family with vast investments in Kenya, Tanzania, Middle East, South Africa, Uganda, South Sudan,and the United Kingdom. Family members also own real estate properties abroad.
In January last year, the revenue collection agency clamped down on two container freight stations associated with the family over claims of tax evasion. The Joho family sued KRA and the tax collection agency applied to settle the matter out of court. The dispute has since been resolved.
Then, Orange Democratic Movement (ODM) leader Raila Odinga accused KRA of being misused by the State to harass and intimidate Joho over his criticism of the Government.