The House Judiciary Committee has launched a sweeping probe into President Donald Trump to discern if his Administration and associates obstructed justice and engaged in public corruption or any other abuse of power.

The committee, helmed by Rep. Jerrold Nadler, announced Monday that it had sent out 81 requests for documents to start building its record for the investigation.

“We have seen the damage done to our democratic institutions in the two years that the Congress refused to conduct responsible oversight,” Nadler said in a statement Monday. “Congress must provide a check on abuses of power. Equally, we must protect and respect the work of Special Counsel, but we cannot rely on others to do the investigative work for us.”

Included in the requests were the Trump Organization, as well as several employees invoked by former Trump attorney Michael Cohen during his hearing last week before the House oversight committee: Chief Financial Official Allen Weisselberg, Executive Vice President Matthew Calamari, and President Trump’s longtime personal assistant Rhona Graff. The President’s two sons, Eric Trump and Donald Trump Jr., also received requests, as did the White House and his son-in-law, Jared Kushner.

Nadler defined obstruction of justice as any interference from President Trump and his associates in criminal investigations and any “alleged cover-up violations of the law,” and public corruption as any possible violation of the emolument clause and “conspiracy to violate federal campaign and financial reporting laws.” Abuse of power was defined in part as “attempts to misuse the power of the Office of the Presidency,” which also included attacks on the press, law enforcement and judiciary.

A counsel on the committee acknowledged that abuse of power, which appeared to have the broadest scope, is something the committee is particularly interested in exploring.

Broadly speaking, this means that a panoply of topics and people that are already being investigated by either Special Counsel Robert Mueller, the Southern District of New York – or both – are now under an additional microscope from Congress. Weisselberg, for instance, was reportedly given immunity by the Southern District of New York to testify about Cohen, but now faces questioning from Congress as well.

The laundry list of topics that repeatedly came up in the requests include the project the Trump organization was developing in Moscow, which coincided with the 2016 election; the hush-money payments Cohen made to porn star Stormy Daniels, for which Trump reimbursed him; contacts between Trump associates and Russian officials during the 2016 election; and the firing of former FBI Director James Comey.

Several people cooperating in Mueller’s probe, including Cohen Michael Flynn, Sam Nunberg and George Papadapoulos received requests as well. Both the Southern District of New York and Mueller are aware of the committee’s probe and have approved this document request, according to a counsel on the committee. Nadler is largely allowing the documents provided to the committee to be restricted to what has already been handed over in those investigations.

Nadler had said Sunday on ABC News that his committee was planning on issuing the document requests, and that Weisselberg and the White House would be included, but declined to provide additional specifics.

All of the recipients have until March 18 to provide the requested documents voluntarily. While the committee is expecting some resistance, lawmakers are hopeful that the restriction Nadler is allowing on the documents will help in that regard. After that time, if recipients have stopped responding or negotiating with the committee, it is likely that the committee would authorize subpoenas.

White House Press Secretary Sarah Huckabee Sanders said in a statement Monday before Nadler officially sent the list of requests that the White House had received its letter from the committee. “The Counsel’s Office and relevant White House officials will review it and respond at the appropriate time,” she said.

Trump told reporters when asked about the request that he “cooperates all the time with everybody” but that the probe is a “political hoax.”

More document requests are expected after this first wave, according to a committee counsel.

Write to Alana Abramson at Alana.Abramson@time.com.