Dozens of people with connections to President Donald Trump and his associates will receive document requests this week, as the House Judiciary Committee starts a broad new probe looking at possible obstruction of justice, corruption and abuse of power.
Trump assailed the investigations as "a big, fat, fishing expedition in search of a crime".
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.
Democrats want to know whether Trump sought to illegally obstruct the Justice Department's investigation into possible collusion with Russian Federation.
The former White House counsel did not indicate in his interview that he has any insider information about when Mueller will hand his final report to Attorney General William Barr, who won't recuse himself from the investigation.
Should Trump face impeachment proceedings in the House, Nadler would oversee those.
The list of document requests also includes the National Rifle Association and Trump's embattled charitable foundation, which he is shutting down after agreeing to a court-supervised process.
She said White House lawyers and "relevant White House officials" would review the Judiciary Committee's demand for documents and "respond at the appropriate time".
Circling back to the question of whether the widespread House investigations are warranted, therefore, House Judiciary Chairman Jerry Nadler explained it this way: "Before you impeach somebody, you have to persuade the American public that it ought to happen".
"It's all a hoax", Mr Trump told reporters at the White House.
Today, Chairman Nadler opened up a disgraceful and abusive investigation into exhausted, false allegations already investigated by the Special Counsel and committees in both Chambers of Congress. Chairman Nadler and his fellow Democrats have embarked on this fishing expedition because they are terrified that their two-year false narrative of "Russia collusion" is crumbling.
Mr Nadler's probe also touches on matters including the firing of former Federal Bureau of Investigation director James Comey and hush payments made to women who say they had affairs with Mr Trump. Though Special Counsel Robert Mueller may be nearing a final report, these congressional probes signal that scrutiny of Trump's business ties, policies and presidential campaign is far from over.
Lieu pointed out that Kushner's forms had "over 100 omissions, including the infamous June 2016 meeting he attended in Trump Tower where Russian agents offered "dirt" on then-candidate Hillary Clinton".
If the Trump Organization has knowingly profited handsomely by this business, it could violate the United States constitution's "emoluments" rules which seek to prevent a president from making a business out of his White House tenure. At the same time, maintained that Mueller's investigation is "never going to be over".
The president's attorneys were noncommittal during the conversation with Cohen's lawyer, Stephen Ryan, the people said. Republicans in Congress have made clear they will fight the attempt by Democrats to get Trump's tax returns - insisting that the effort is entirely political and amounts to an invasion of privacy.