WASHINGTON (Reuters) – The Democratic chairman of the U.S. House of Representatives tax committee has asked Treasury Secretary Steven Mnuchin to testify next week about the partial government shutdown’s impact on the upcoming federal tax filing season, the panel said on Thursday.

The request, contained in a Jan. 16 letter to Mnuchin from House Ways and Means Committee Chairman Richard Neal, comes days after the Internal Revenue Service said it would bring more than 46,000 furloughed employees back to work to handle tax filings, refunds and other tasks.

Democrats have been mulling the possibility of hearings since the White House said earlier this month that the IRS, the federal government tax agency that Treasury oversees, would deliver tax returns during the shutdown.

Neal invited Mnuchin to appear before the House committee on Jan. 24 at 10:30 a.m. EST (1530 GMT) Treasury officials had no immediate response to the invitation.

The Democratic-led committee said in a statement that the hearing would give Mnuchin an opportunity to brief lawmakers and the public about how the ongoing shutdown has affected the IRS and Treasury, including services for taxpayers.

About one-quarter of the federal government shut down on Dec. 22 over President Donald Trump’s demand for $5.7 billion to fund a wall along the U.S.-Mexico border, which Democrats oppose. The shutdown entered its 27th day on Thursday, with no end in sight for nearly 800,000 federal employees who are no longer being paid.

Meanwhile, the U.S. tax filing season is set to begin on Jan. 28 and last until the April 15 filing deadline.

On Wednesday, the IRS said it would give some taxpayers a break by waiving penalties for many who have had too little federal income tax withheld from their pay last year, or who paid less than their estimated tax liabilities.

After a sweeping Republican overhaul of the U.S. tax system, the IRS released updated federal tax withholding tables last year to reflect adjustments in the tax law. But tax authorities later acknowledged that the tables did not fully factor in some changes including exemptions for dependents and reduced itemized deductions.

Democrats, who criticized the withholding tables as inaccurate, are now raising questions whether the IRS can provide refunds on time.