JEFFERSON CITY, Mo. (AP) — Missouri Gov. Mike Parson is accusing state lawmakers of “grandstanding” by holding numerous hearings to discuss a tax refund problem caused by a mistake on state tax withholding tables.

Parson on Wednesday also defended Revenue Director Joel Walters’ handling of the error that could sharply reduce or eliminate refunds for thousands of Missouri taxpayers on their state income tax returns for 2018.

The Republican governor responded after Walters appeared Wednesday at another special Missouri House committee hearing on the issue.

“Since this year’s session began, Director Walters has testified at ten hearings where the withholding issue was discussed. Our office is aware of the decade old mistake that was found in the withholding tables and have worked with the department to correct the problem and focus on solutions, not political grandstanding,” Parson said in a statement to the St. Louis Post-Dispatch.

The error, which has been corrected, means employers didn’t take withhold enough money from workers’ paychecks throughout 2018, so employees will have to pay a larger share of their tax bill when they file their taxes this year.

Parson also criticized lawmakers and taxpayers for depending on larger refunds, saying they should adjust their W-4 forms to pay as little to the government as possible throughout the year, which would give them more money in their paychecks but also reduce refunds.

Critics have said the Revenue Department didn’t do enough to notify Missouri residents when the miscalculation was discovered, and Walters agreed with that assessment during a hearing Wednesday before the House Special Committee on Government Accountability.

“We didn’t know how big the issue will be,” Walters said.

Committee chairman Robert Ross, R-Yukon, who has led the inquiry into Walters’ leadership on the problem, said the attempts to notify residents about the effects of the changes through social media failed miserably.

He noted that the Revenue Department has only 982 Facebook followers and about 2,000 Twitter followers.

“The memo’s not getting out there, director,” Ross said.

But Parson said Walters has held numerous one-on-one meetings with state officials and given public testimony that clearly identified the issue and the department’s plans to help people who may be affected.

House Minority Leader Crystal Quade, D-Springfield, said Parson’s comments were “deeply disappointing.”

“Most Missourians are not certified public accountants or tax policy experts, and since they never needed to change their withholding information in previous years, it is unreasonable to expect they should have known to do so without Gov. Parson’s Department of Revenue making robust efforts to inform them, which it completely failed to do,” Quade said. “Right now, we must do everything possible to help the countless Missourians who are wondering how to pay tax bills they didn’t know they were going to owe.”