The House committee investigating the January insurrection at the U.S. Capitol is demanding a trove of records from federal intelligence and law enforcement agencies, showing the sweep of the lawmakers’ review of the deadly attack by a mob of Donald Trump supporters.

The request seeks information about the events leading up to the 6 January riot, including communication within the White House under then-President Trump and other agencies, and information about planning and funding for rallies held in Washington. Among them is an event at the Ellipse, near the White House, featuring remarks by Trump where he egged on a crowd of thousands before loyalists stormed the Capitol.

The requested documents are just the beginning of what is expected to be lengthy, partisan and rancorous investigation. In a statement on Wednesday evening, Trump accused the committee of violating “long-standing legal principles of privilege.”

“Executive privilege will be defended, not just on behalf of my Administration and the Patriots who worked beside me, but on behalf of the Office of the President of the United States and the future of our Nation,” Trump said.

Committee members are also considering asking telecommunications companies to preserve phone records of several people, including members of Congress, to try to determine who knew what about the unfolding riot and when they knew it.

The demands are being made for White House records from the National Archives, along with material from the departments of Defense, Justice, Homeland Security and Interior, as well as the FBI and the Office of the Director of National Intelligence.

The committee is also seeking information about efforts within the Trump administration to push the president’s baseless claims of election fraud and any efforts to try to overturn the results of November’s election or to “impede the peaceful transfer of power.”

The request for the National Archives and Records Administration is 10 pages long. The committee is seeking “All documents and communications within the White House on January 6, 2021” related to Trump’s close advisers and family members, the rally at the Ellipse and Trump’s Twitter feed. It asks for his specific movements on that day and communications, if any, from the White House Situation Room. Also sought are all documents related to the claims of election fraud, as well as Supreme Court decisions on the topic.

Rep. Bennie Thompson, D-Miss., is heading the committee, appointed by House Speaker Nancy Pelosi, D-Calif., after all but two Republicans opposed the creation of the 13-person panel.

The committee so far has heard from police officers who were at the Capitol on that day. A Capitol Police officer who fatally shot protester Ashli Babbitt was cleared months ago of criminal wrongdoing and was cleared internally by the department this week, and was planning to reveal his identity in an NBC interview to air Thursday.

Most in the GOP argued that the majority-Democratic committee would conduct a partisan inquiry. Thompson did not identify the lawmakers whose records the committee would seek, but he has said officials would be contacting communication companies, social media platforms and other tech giants.

House Republican leader Kevin McCarthy of California, who had been in touch with Trump from the besieged Capitol, again dismissed the committee’s investigation as “so political.”

When he was asked whether he would turn over his own phone logs from 6 Jan, he said on Wednesday, “I told the American public who I talked to that day,” referring to his television news appearances that day.

Thompson, in a written statement, said the committee’s work was rooted in apolitical fact-finding.

“Our Constitution provides for a peaceful transfer of power, and this investigation seeks to evaluate threats to that process, identify lessons learned and recommend laws, policies, procedures, rules, or regulations necessary to protect our republic in the future,” he said.