Texas Gov. Greg Abbott and Houston Mayor Sylvester Turner are clashing over how to pay for Hurricane Harvey cleanup – with Turner threatening to raise taxes if the state doesn't free up more funding.

The Democratic mayor wants the GOP governor to tap into the state’s nearly $10 billion rainy day fund, warning he may have to raise the city’s property tax if Abbott doesn’t pay.

Abbott responded by accusing Turner of turning this into a "hostage" situation.

"It raises a concern that the mayor seems to be using this as hostage to raise taxes when, in reality, the city of Houston is sitting on hundreds of millions of taxpayer dollars that he's not tapping into," Abbott said.

Houston Mayor Sylvester Turner, center, with Houston Texans Shane Lechler, left, and J.J. Watt, second right, distribute relief supplies to people impacted by Hurricane Harvey on Sunday, Sept. 3, 2017, in Houston. Watt's Hurricane Harvey Relief Fund has raised millions of dollars to help those affected by the storm. (Brett Coomer/Houston Chronicle via AP, Pool) (AP)

The disagreement began when Turner sent Abbott an open letter stating the storm “caused local governments to incur unanticipated costs far above and beyond their budgets” and that rainy day funds should be used.

Turner proposed a 3.6 percent property tax increase for one year if he doesn’t get the rainy day funds. The mayor’s office said the tax hike would cost the average Houston homeowner $4.03 per month for the year.

Turner gave examples of the city’s costs that are “a scale beyond our savings,” citing at least $25 million in debris removal costs, a $15 million deductible for the city’s property insurance to kick in and a $100 million cap on insurance. According to the city’s insurance broker, another $100 million policy for future flooding would cost $10 million, Turner wrote.

“During Hurricane Harvey, approximately 27 trillion gallons of rain fell in Texas. There hardly seems a more appropriate use of the nearly $10 billion of taxpayer dollars in the fund than on a recovery from this storm,” Turner wrote.

Houston has already used $20 million in emergency funding but it’s not enough, according to Turner.

Abbott, however, said Turner has all the money he needs. The city has special tax reinvestment zones, but a city spokesman said the city can’t use that money which is for drainage projects to prevent future flooding.

The Associated Press contributed to this report.