Democrats in the US House of Representatives are about to vote on whether to hold Attorney General William Barr in contempt of Congress.
The judiciary committee took action after Mr Barr refused to submit an unredacted version of Special Counsel Robert Mueller’s report.
President Donald Trump has 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.
The judiciary committee will vote on Wednesday on recommending a contempt resolution against the attorney general for a full House vote.
Democratic lawmakers took action after Mr Barr did not comply with a legal order to release the Mueller report minus the redactions.
The 448-page Mueller report was released last month with parts blacked out, including information that is classified or linked to pending investigations.
The special counsel did not conclude there was a criminal conspiracy between Moscow and the Trump campaign to influence the 2016 US presidential election.
