US Attorney General William Barr should be held in contempt of Congress, the House of Representatives judiciary committee has ruled.
Democrats on the committee took the rare step as tensions increased over the special counsel’s findings on Russian interference.
President Donald Trump hit back by asserting executive privilege over the report, shielding it from public view.
The White House and Congress accused each other of abusing power.
Special Counsel Robert Mueller’s report did not conclude that there was a criminal conspiracy between Moscow and the Trump campaign to influence the 2016 US presidential election.
However, Mr Mueller did detail 10 instances where Mr Trump possibly attempted to impede the investigation.
Meanwhile the Senate Intelligence Committee has subpoenaed Donald Trump Jr, one of President Trump’s sons, to legally force him to testify.
He will be expected to answer questions about testimony he gave to the Senate Judiciary Committee in September 2017, which was later contradicted by the president’s former lawyer Michael Cohen, sources from Congress tell Reuters news agency.
Mr Trump Jr will also probably be quizzed on his connections in Russia.
It is the first known legal summons issued to a member of the president’s family in connection with the investigation.
Why was there a contempt vote on Barr?
Democratic lawmakers put forward the measure after Mr Barr did not comply with a legal order to release the Mueller report without the redactions.
The 448-page report was released last month with parts blacked out, including information that is classified or linked to pending investigations.
After the legal order, Mr Barr formally asked the president to assert his right to executive privilege to stop the unredacted version of the report being released.
On Wednesday, the judiciary committee voted 24-16 along party lines to refer a contempt citation against the attorney general for a full House vote.
Democrats say they need to see the full report and its underlying evidence to investigate possible obstruction of justice by Mr Trump.
House judiciary chairman Jerrold Nadler said afterwards that the vote was a “grave and momentous step”.
He called the Trump administration’s refusal to provide the full Mueller report to Congress “an attack on the essence of our democracy”.
“We have talked for a long time about approaching a constitutional crisis, we are now in it,” the New York Democrat told reporters.
Earlier, Doug Collins, a leading Republican on the committee, said Democrats were acting out of anger and fear “without any valid legislative reason”. BBC News