House Democrats sent a letter Wednesday to acting Attorney General Matthew Whitaker demanding that he appear before the House Judiciary Committee by Jan. 29, saying that the government shutdown is no excuse for delaying his testimony.

Whitaker previously wrote to Chairman Jerrold Nadler of New York that he would appear before the committee in mid-February “so long as the Department is at least two weeks removed from a partial government shutdown.”

Nadler rejected that proposed timeline in a letter to Whitaker on Wednesday.

“We are willing to work with you to identify a mutually identifiable date for your testimony, but we will not allow that date to slip past January 29, 2019, the day of the President’s scheduled address to Congress, when we know you will be in Washington,” Nadler wrote.

Nadler cited internal Justice Department guidance from 1995, when the Office of Legal Counsel wrote that, in the event of a government shutdown, “the Department may continue activities such as providing testimony at hearings if the Department’s participation is necessary for the hearing to be effective.”

Whitaker spoke with House Democrats on the phone in November and agreed to appear before the committee for testimony once Democrats took over control of the House. The attorney general is dragging his feet, Nadler suggested in his letter, even though Democrats want to ask him about protecting the integrity of the special counsel led by Robert S. Mueller III, bills that address voting rights and immigration, and a host of other policy issues.

Whitaker has not appeared for testimony in the three months since he took over from fired Attorney General Jeff Sessions. Sessions last appeared on Nov. 14, 2017.

“It has been nearly 15 months since Attorney General Sessions testified before the Committee,” Nadler wrote in the letter Wednesday. “It is past time for the Committee to conduct oversight of the Department.”