 -- A highly anticipated House Intelligence Committee interview with Stephen Bannon has been postponed until next week, the committee said on Tuesday, as negotiations continue over the terms of his appearance.

Bannon, the former White House chief strategist, was expected to skip his scheduled appearance Tuesday before the House Intelligence Committee, according to sources familiar with his plans. The move sets the stage for a showdown with lawmakers who had issued a bipartisan subpoena for his testimony.

“This is unacceptable, and the Committee remains united on this matter — the Committee’s subpoena remains in effect and his interview has been rescheduled for next week. Testifying before the Special Counsel does not obviate Mr. Bannon’s obligations under the subpoena issued by the Committee," Rep. Adam Schiff, D-California, the committee's ranking Democrat said on Tuesday in a statement. "Should Bannon maintain his refusal to return and testify fully to all questions, the Committee should begin contempt proceedings to compel his testimony.”

Bannon was ordered to return to Capitol Hill Tuesday morning after a marathon meeting with the committee behind closed doors last month, where he refused to answer the committee’s questions about his time working for Trump during the transition or in the White House.

Bannon declined to answer the questions in light of executive privilege concerns, a claim of privilege Rep. Adam Schiff, the panel’s top Democrat, called “breathtaking.”

Monday evening, Rep. Mike Conaway, R-Texas, the Republican leading the panel’s Russia probe, told reporters he expected Bannon to appear.

Two sources close to Bannon tell ABC News that the committee has still not determined the proper scope of questioning with the White House, and that the White House has said its position “has not changed on declining to authorize Bannon to answer questions” about his time working for Trump, according to one of the sources.

That source noted Bannon is willing to discuss “anything and everything” with special counsel Robert Mueller.

The White House and the president’s legal team have not responded to requests for comment.

The committee, in light of Bannon’s expected absence, could move to hold him in contempt, beginning a process that could end in a full House vote authorizing GOP leaders to seek criminal charges against Bannon.