He plans on not answering

How about the Committee subpoenas him to appear?

"The Acting Attorney General will testify that at no time did the White House ask for, or did the Acting Attorney General provide, any promises or commitments concerning the Special Counsel's investigation," Assistant Attorney General Stephen Boyd writes in the new letter obtained by CNN. "With respect to the Special Counsel investigation, the Department has complied with the Special Counsel regulations, and the Acting Attorney General will make clear that there has been no change in how the Department has worked with the Special Counsel's office."

A senior Justice Department official told CNN that the bottom line is that the Department is not aware of any precedent for the authorization of a subpoena before questioning.

"This is a breach of the agreement," and a "striking departure from long-standing processes."

Democrats approved the subpoena over the objection of Republicans, who accused Nadler of authorizing a pre-emptive subpoena as "political theater" with questions designed to embarrass the acting attorney general.

The resolution passed on a party-line vote, 23-13.

[...]

Nadler said that authorizing a subpoena for Whitaker was necessary because Whitaker failed to tell the committee whether the Trump administration would invoke privilege with respect to a series of questions they intend to ask about Whitaker's conversations with the White House about special counsel Robert Mueller's probe and his decision not to recuse himself from the matter.

  CNN

There are 10 more Democrats than Republicans on the Committee?

At any rate, the shoe is on the other foot now, and the Republicans don't like the fit.

Nadler argued in a letter to Whitaker that he could not claim the White House reserved the right to claim executive privilege to avoid answering those questions. He asked Whitaker to consult with the White House ahead of the hearing and tell the committee whether he would invoke privilege, though Whitaker has not responded to Nadler's letter as of Thursday morning.

There is a bit of theater to it, to be honest. I understand Nadler's concern, but he has no authority to force Whitaker to state ahead of time whether he intends to claim executive privilege on any particular question.

"The subpoena will only be issued if he refuses to answer questions on a speculative basis of privilege," Nadler said. "If he does not show up — though I do expect he will — but if he refuses to answer questions he ought to answer, then we will have the tools we need to ensure that we may adequately meet our own responsibilities."

Republicans slammed Nadler for pre-emptively planning a subpoena for a witness who had voluntarily agreed to testify, saying it was setting a troubling precedent.

"A subpoena should only follow a breakdown of the accommodation process and as a last resort against persons seeking to frustrate legitimate oversight on this committee," said Rep. Doug Collins of Georgia, the committee's top Republican. "There has been no breakdown here."

Nor has any subpoena been served.

Whitaker has been undertaking significant preparations ahead of the hearing, including conducting briefings with every DOJ component and participating in several mock hearings, according to the officials.

He's going to have to resort to just refusing to answer, be it under a claim of executive privilege or something else, because he is no match for the Committee. He was sweating bullets at a press conference.

...but hey, do what you want...you will anyway.