House Judiciary Chairman Jerrold Nadler Jerrold (Jerry) Lewis NadlerDemocrats shoot down talk of expanding Supreme Court Schumer: 'Nothing is off the table' if GOP moves forward with Ginsburg replacement Top Democrats call for DOJ watchdog to probe Barr over possible 2020 election influence MORE (D-N.Y.) is asking four other top committee leaders to share any documents or materials they think could be related to his committee’s investigation into possible obstruction and potential abuses of power by President Trump Donald John TrumpFederal prosecutor speaks out, says Barr 'has brought shame' on Justice Dept. Former Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick MORE.

In a letter on Thursday, Nadler wrote to Intelligence Chairman Adam Schiff Adam Bennett SchiffSchiff to subpoena top DHS official, alleges whistleblower deposition is being stonewalled Schiff claims DHS is blocking whistleblower's access to records before testimony GOP lawmakers distance themselves from Trump comments on transfer of power MORE (D-Calif.), Oversight and Reform Chairman Elijah Cummings Elijah Eugene CummingsBlack GOP candidate accuses Behar of wearing black face in heated interview Overnight Health Care: US won't join global coronavirus vaccine initiative | Federal panel lays out initial priorities for COVID-19 vaccine distribution | NIH panel: 'Insufficient data' to show treatment touted by Trump works House Oversight Democrats to subpoena AbbVie in drug pricing probe MORE (D-Md.), Financial Services Chairwoman Maxine Waters Maxine Moore WatersPowell, Mnuchin stress limits of current emergency lending programs Pelosi: House will stay in session until agreement is reached on coronavirus relief Omar invokes father's death from coronavirus in reaction to Woodward book MORE (D-Calif.) and Foreign Affairs Chairman Eliot Engel Eliot Lance EngelHouse panel halts contempt proceedings against Pompeo after documents turned over Engel subpoenas US global media chief Michael Pack The Hill's Morning Report - Sponsored by The Air Line Pilots Association - Pence lauds Harris as 'experienced debater'; Trump, Biden diverge over debate prep MORE (D-N.Y.) to ask them to provide such information as Nadler's committee weighs whether to introduce articles of impeachment against the president.

"I am writing to request information, including documents and testimony, depositions, and/or interview transcripts, that you believe may be relevant to the Judiciary Committee's ongoing impeachment investigation relating to President Trump," Nadler wrote. "I look forward to our Committees working together on this matter of the highest constitutional importance." ADVERTISEMENT

Nadler said this request to pool information comes after the Judiciary and Intelligence panels agreed to share grand jury information if the committee wins its lawsuit seeking such materials. By asking other House investigators to share information, Nadler is expanding his probe to include more of the lower chamber.

"The requests described herein would build on that sharing agreement and would similarly allow for sensitive or confidential information to be received in executive session as needed," Nadler wrote.

He also noted that such sharing is consistent with House rules, while noting the "information shall be subject to any requirements and limitations imposed by law, House Rules, and the rules of our respective Committees."

The move comes as the Judiciary Committee is examining almost a dozen possible episodes of obstruction by Trump as laid out by former special counsel Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE.

While Mueller's investigation did not find sufficient evidence that members of the Trump campaign coordinated with Russia during the 2016 presidential election, the former special counsel did not make a determination either way on obstruction. Attorney General William Barr Bill BarrFederal prosecutor speaks out, says Barr 'has brought shame' on Justice Dept. Why a backdoor to encrypted data is detrimental to cybersecurity and data integrity FBI official who worked with Mueller raised doubts about Russia investigation MORE and other top Justice Department officials ultimately made the decision that the evidence in the report did not reach the threshold to charge Trump.

Democrats, who have dismissed Barr's determination, say it is up to them to decide whether the president obstructed justice and whether his actions reach the threshold of committing "high crimes and misdemeanors."

At the same time Republicans have blasted Democrats, accusing them of putting on a political charade that aims to damage Trump ahead of 2020, particularly by replaying the Mueller probe.

But as the Democrat-led committee has sought to investigate obstruction by Trump, it has encountered strong opposition from the White House, particularly with the Trump administration ordering former and current White House officials not to testify.

Earlier this month, the committee filed a civil lawsuit to enforce a subpoena for testimony from former White House counsel Don McGahn, arguing that if they win that case, other former and current White House aides would also be compelled to appear on Capitol Hill.

McGahn is seen as a key witness, particularly because of his testimony to Mueller that Trump ordered him to have the special counsel removed after the president learned that he was under investigation for obstruction.

The White House has argued that under the standard of immunity, confidential protections offered to the executive branch apply to current and former aides, effectively preventing them from disclosing what took place during their time in the administration.

While both Republican and Democratic administrations have invoked the immunity concept, legal experts say there is virtually no case law on the subject, with some predicting the White House is likely to lose if it's challenged in court.

Last week, the committee also issued two subpoenas seeking the public testimony of former campaign manager Cory Lewandowski and former White House deputy chief of staff Rick Dearborn by mid-September.