Treasury Secretary Steven Mnuchin rebuffed a Democratic invitation Thursday to testify next week on the impact of the government shutdown, offering instead to have senior Treasury officials appear before Congress.

House Ways and Means Committee Chairman Richard Neal, D-Mass., invited Mnuchin earlier in the day to testify before his panel next Thursday, to discuss the Internal Revenue Service’s shutdown contingency plan to bring back more than half the agency’s workforce, much of it focused on the annual tax filing season.