WASHINGTON (Reuters) - Democrats in the U.S. Congress unleashed an unexpectedly sweeping series of demands in their investigations of President Donald Trump on Monday, seeking information about his communications with Russian President Vladimir Putin and documents from 81 sources in an obstruction probe.

The heads of the House of Representatives Intelligence, Foreign Affairs and Oversight committees wrote to the White House and Secretary of State Mike Pompeo seeking documents and interviews with personnel about Trump’s conversations with Putin.

The lawmakers expressed concern about media reports that Trump seized notes on at least one meeting with the Russian leader and tried to destroy records about those talks.

“These allegations, if true, raise profound national security, counterintelligence, and foreign policy concerns, especially in light of Russia’s ongoing active measures campaign to improperly influence American elections,” Chairmen Adam Schiff, Elliot Engel and Elijah Cummings wrote in their letter.

The White House pushed back against their demands, with a spokesman saying it was within the president’s constitutional authority to have “candid one-on-one conversations with foreign heads of state.”

“The president may choose to share, or not share the contents of those conversations publicly as such discussions – like all diplomatic discussions – are often sensitive in nature,” the spokesman said on condition of anonymity, urging the panels to respect Trump’s authority to conduct foreign policy.

The request for information about communications with Putin followed the powerful House Judiciary Committee’s demand for documents from a who’s who of Trump’s turbulent world, targeting 81 people, government agencies and other groups in a probe into possible obstruction of justice or abuse of power.

The Republican president faces investigations from several congressional committees, as well as the 22-month-long federal special counsel probe into Russian interference in the 2016 presidential election and whether the Trump campaign worked with Moscow to sway the outcome.

When they took control of the House in January, Democrats promised investigations on multiple fronts involving Trump, saying their Republican counterparts had ignored red flags coming out of the White House.

The Judiciary Committee listed Trump family members, current and former business employees, Republican campaign staffers and former White House aides, as well as the FBI, White House and WikiLeaks were listed as recipients of documents requests.

The panel also named the president’s sons, Donald Trump Jr. and Eric Trump, White House aide and Trump son-in-law Jared Kushner, Trump Organization Chief Financial Officer Allen Weisselberg, former U.S. attorney general Jeff Sessions and former White House counsel Don McGahn.

“We have seen the damage done to our democratic institutions in the two years that the Congress refused to conduct responsible oversight,” said U.S. Representative Jerrold Nadler, Judiciary Committee chairman. “Congress must provide a check on abuses of power.”

TRUMP: IT’S A ‘HOAX

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At the White House, Trump was asked if he would cooperate with Nadler’s probe. “I cooperate all the time with everybody,” he said before adding: “You know the beautiful thing? No collusion. It’s all a hoax...It’s a political hoax.”

A committee lawyer told reporters the immediate aim is to amass a large trove of evidence to guide the investigation and help decide which witnesses to approach. The panel is prepared to use its subpoena power if needed, the lawyer said.

Among the committee’s aims is determining whether Trump obstructed justice by ousting perceived enemies at the Justice Department, such as former FBI Director James Comey, and abused his presidential power by possibly offering pardons or tampering with witnesses.

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Comey was leading an investigation into Russian activities in the 2016 U.S. presidential election and possible collusion with Trump’s campaign when the president fired him in May 2017.

The investigation was subsequently taken over by Special Counsel Robert Mueller, who is expected to end his investigation and report his findings in coming weeks.

The Judiciary Committee is also probing a discussion a lawyer for former Trump attorney Michael Cohen had with Trump’s lawyers about the possibility of a pardon for Cohen, the Wall Street Journal reported, citing people familiar with the discussions.

The discussion happened in the weeks after FBI agents raided Cohen’s home, office and hotel room, the Journal reported. The president’s lawyers dismissed the idea of a pardon at the time, the newspaper said. Cohen later pleaded guilty to tax evasion, bank fraud, lying to Congress and campaign finance violations.

The Judiciary Committee is looking at whether Trump has used the White House for personal enrichment in violation of the Constitution’s emoluments clause.

Representatives for the White House and Justice Department said the requests are being reviewed.

Republicans in Congress accuse Democrats of pursuing an impeachment agenda against Trump as part of a political strategy to reclaim the White House in the 2020 election.

Democrats say talk of impeachment is premature. They say the first step is to initiate proper investigations, which were missing in the first two years of Trump’s presidency, when his fellow Republicans controlled the House of Representatives.

Some of those the committee is seeking documents from are among the dozens charged by Mueller. They include former Trump national security adviser Michael Flynn, former campaign chairman Paul Manafort, former Trump adviser Roger Stone and Cohen.

Also on the committee’s list are others who worked on Trump’s 2016 campaign or in the White House, such as Hope Hicks, Steve Bannon, Reince Priebus and Sean Spicer; Rhona Graff, a long-time executive assistant at the Trump Organization; and David Pecker, chief executive of American Media Inc, which publishes the supermarket tabloid the National Enquirer.

Trump maintains that his campaign did not collude with Russia and has repeatedly attacked the investigation on Twitter.

Democrats say Cohen’s testimony before the House Oversight Committee last week directly implicated Trump in various crimes including campaign finance violations.