The US House of Representatives Judicial Affairs Committee issued an official memo asking the Justice Department to hand over a full copy of Special Inspector Robert Muller's report on possible Russian intervention in the 2016 election that brought Donald Trump to the White House.
Commission President Jerry Nadler said he believed President Trump had committed a crime to obstruct justice, while the Justice Department described the House of Representatives' memorandum as too fast and unnecessary.
Democratic leaders in the US Congress have rejected a proposal by Justice Minister William Bar to allow them to see a less concise version of Muller's report.
Six House Democrats, led by House Speaker Nancy Pelosi and Senate Minority Leader Chuck Schumer, reiterated in a letter to the Justice Minister that the Muller report be made available to Congress without any abbreviations or omissions.
But Democratic lawmakers said they were ready to discuss the matter with the Justice Department to reconcile the two sides.
"The Mueller report paints a disturbing picture of a president who was weaving a network of deceit, lies and improper behavior, acting as if the law did not apply to him," Pelosi said.
"The measures of isolation are part of our constitutional responsibility," said Congressional Democratic Representative Elhan Omar. "We have the duty to investigate whether the president has committed abuses deserving of isolation, including obstruction of justice, violation of the Wages Act, complicity and abuse of power."