Jan. 6 panel members considering contempt charges for Steve Bannon

WASHINGTON (AP) - A lawyer for Steve Bannon said Friday that Bannon won't comply with a congressional investigation into the Jan. 6 insurrection at the Capitol because former President Donald Trump is asserting executive privilege to block demands for testimony and documents.

"As such, until these issues are resolved, we are unable to respond to your requests for documents and testimony," attorney Robert Costello said in a letter to the special House committee investigating the attack.

But he also said that Bannon, a former aide to Trump who had contact with him the week of the Capitol attack, is prepared to "comply with the directions of the courts" when and if they rule on the issue.

The directions from Trump to Bannon raise the prospect that three other aides who were subpoenaed — Mark Meadows, Trump’s former chief of staff; Dan Scavino, the former deputy chief of staff for communications and Kashyap Patel, a former Defense Department official — may also refuse to comply. None of the three have yet responded to the subpoenas, including the requests for documents that were due on Thursday. The committee has scheduled interviews for next week.

RELATED: Biden waives executive privilege on Trump documents related to Jan. 6 probe

Costello's letter to the committee includes excerpts from a letter sent to Bannon by Justin Clark, a lawyer for Trump. Clark says the documents and testimony could include information that is "potentially protected from disclosure by executive and other privileges, including among others the presidential communications, deliberative process and attorney client privileges."

Clark wrote to Bannon that "President Trump is prepared to defend these fundamental privileges in court."

Spokespeople for Trump have not returned messages seeking comment. Trump said in a statement last month that he would "fight the Subpoenas on Executive Privilege and other grounds, for the good of our Country."

The move sets the stage for a likely clash with House Democrats who are investigating the roles of Trump and his allies in the run-up to the riot, when a large mob of Trump supporters broke into the Capitol as Congress was certifying the results of the presidential election won by Democrat Joe Biden. The committee is rapidly issuing subpoenas to individuals who are either connected to Trump or who helped plan the massive rally on the morning of Jan. 6 at which he told his supporters to "fight like hell."

Bannon is the only one of the top Trump aides subpoenaed on Sept. 23 who was not working for the Trump administration on Jan. 6. It is unclear whether that will affect his standing if the case moves to the courts.

Patel said in a statement that he will "continue to tell the American people the truth about January 6" but would not say whether he would comply. Scavino and an aide to Meadows did not immediately respond to requests for comment.

RELATED: Facebook whistleblower to speak with Capitol riot investigative committee

Committee members have said they plan to try and move swiftly to obtain testimony and documents should any witnesses refuse to cooperate. Rep. Adam Schiff, D-Calif., tweeted Thursday that if the Trump associates do not comply, "they can be subject to criminal contempt."

Charging the Trump associates with contempt could still be a lengthy process, including votes of the full House and potential court proceedings.

The issue can also become more complicated because Trump no longer is in office. As the former president, he cannot directly assert privilege to keep witnesses quiet or documents out of the hands of Congress. As the current president, Biden will have some say in the matter.

The Select Committee to Investigate the January 6th attack has issued more than a dozen subpoenas to people linked to plans for the Jan. 6 protests, including three additional witnesses announced Thursday. Those individuals would be less likely to get help from Trump’s executive privilege claims, since they did not work for the White House and most of them did not have regular contact with Trump.

The committee chairman, Rep. Bennie Thompson, D-Miss., said additional subpoenas had gone to Ali Abdul Akbar, also known as Ali Alexander, and Nathan Martin, as well the organization " Stop the Steal, " to learn more about a rally that was planned on the Capitol grounds at the same time as the larger gathering on the National Mall. The committee earlier subpoenaed 11 other individuals connected to the planning of the larger rally.

According to the committee, Alexander released a statement after the riot linking "Stop the Steal" to the Capitol rally permit and explaining that the intention was to direct attendees of the larger rally to march to the Capitol. The panel cited reports that Alexander had made reference "to the possible use of violence to achieve the organization’s goals" and had been in communication with the White House and members of Congress.

"The rally on the Capitol grounds on January 6th, like the rally near the White House that day, immediately preceded the violent attack on the seat of our democracy," Thompson said in a statement. "Over the course of that day, demonstrations escalated to violence and protestors became rioters."

Thompson said the committee "needs to understand all the details about the events that came before the attack, including who was involved in planning and funding them."