WASHINGTON -- The White House and lawmakers haggled Thursday over what former chief strategist Steve Bannon and other top aides to President Donald Trump can tell Congress as it investigates possible connections with Russia.

Lawmakers on both sides of the aisle have been critical of the White House's sweeping interpretation of executive privilege -- pretty much everything is off limits until the president says it's not.

Bannon had been subpoenaed to return to the House Intelligence Committee on Thursday to face additional questions about his interactions with the president, but documents obtained by The Associated Press show he now has until the week of Jan. 29. The committee gave him more time to "clarify the White House's instructions" regarding what he can tell lawmakers, the documents show.

The postponement of Bannon's interview came after his attorney, Bill Burck, sent a letter to the committee, arguing it had failed to give him proper time to respond or review documents the committee may want to ask him about. According to the letter, obtained by the AP, the committee asked Burck to work with the White House to define the scope of the "privilege the President may wish to assert" over Bannon.

The negotiations will put Burck in the position of working out what one of his clients, Bannon, can say with an office overseen by another client, White House counsel Don McGahn. Burck is representing McGahn in special counsel Robert Mueller's investigation into contacts between the Trump campaign and Russia.

As lawmakers in the closed-door session probed Bannon's time working for Trump, his attorney phoned the White House counsel's office, relaying questions and asking what Bannon could tell Congress, according to a White House official and a second person familiar with the interview.

The answer was a broad one. Bannon couldn't discuss anything to do with his work on the presidential transition or later in the White House itself.

The development brought to the forefront questions about White House efforts to control what current and former aides may or may not tell Congress about their time in Trump's inner circle, and whether Republicans who hold majorities on Capitol Hill will force the issue. It was also the broadest example yet of the White House using executive privilege to limit a witness' testimony without making a formal invocation of that presidential power.

The White House has argued Bannon, like every current and former member of the administration, starts under the assumption he is covered by executive privilege and can only answer certain questions unless Trump explicitly says otherwise.

During his testimony earlier this week, Bannon sought to extend this privilege to his conversations after he had left the White House in August.

According to Burck's letter, Bannon refused to discuss any "advice" he gave Trump after his last day in the White House, though he did answer an undisclosed question about his "communications" with the president.

Bannon's silence provoked bipartisan criticism and prompted the subpoena from the committee's Republican chairman, Devin Nunes of California,

The criticisms echoed those from last summer when Attorney General Jeff Sessions baffled some lawmakers by refusing to answer questions about his conversations with the president, while also maintaining he was not citing executive privilege. Following Sessions' testimony before the Senate Intelligence Committee, Democratic Sen. Sheldon Whitehouse said, "As someone who served in the Justice Department, I would love to know what he is talking about."

Michael Dorf, a constitutional law professor at Cornell University, said while traditionally Congress has required a formal assertion of executive privilege in order for a witness to refuse to answer a question, more recently "we've seen people just not answer questions without asserting privilege."

"It's kind of a game of separation-of-powers chicken that's going on there," he said. "Because nobody knows the full scope of executive privilege -- other than that it's not absolute from the Nixon case -- no one really wants to push it."

Dorf referred to the court case surrounding the Supreme Court's rejection in 1974 of President Richard Nixon's assertion that he could use executive privilege to prevent the release of tape recordings involving him and other aides.

Earlier this week, White House press secretary Sarah Huckabee Sanders said the phone conversations Burck had with the White House counsel's office during the interview were standard procedure.

Burck spoke with Uttam Dhillon, deputy White House counsel, during Bannon's interview. A White House official and a second person familiar with Bannon's interview confirmed the details of the conversations. They spoke only on condition of anonymity because they were not authorized to speak publicly.

While the congressional negotiations play out, Bannon is set to meet with Mueller's investigators for an interview instead of appearing before a grand jury. A person familiar with that issue confirmed the interview. That person was not authorized to speak publicly about private conversations. Peter Carr, a spokesman for the special counsel's office, declined comment.

Bannon is expected to cooperate with Mueller, and if the White House attempts to invoke privilege to keep him from answering Mueller's questions, it would be a departure from other White House interviews.

White House lawyers to date have made documents and witnesses available to Mueller without asserting privileges that could slow the investigation in a protracted legal fight. The goal of the cooperation, from the White House perspective, has been to help the investigation conclude as quickly as possible.