The US Congress is wrestling with the dilemma of what to do with special counsel Robert Mueller’s findings about Donald Trump.

While Mr Mueller declined to prosecute the president for obstruction of justice, he did not exonerate him, all but leaving the question to Congress.

His report provides fresh evidence of Mr Trump’s interference in the Russia probe, challenging legislators to respond.

Robert Mueller
Robert Mueller (Charles Dharapak/AP)

The risks for both parties are clear if they duck the responsibility or prolong an inquiry that, rather than coming to a close, may be just beginning.

“The responsibility now falls to Congress,” said Democrat representative Jerrold Nadler, chairman of the House Judiciary Committee which has the power to launch impeachment proceedings.

Attorney general William Barr sent Congress a redacted version of the report, blacking out several types of material, including classified information, material pertaining to ongoing investigations, and grand jury evidence.

Four pages of the Mueller Report
Four pages of the Mueller Report (Cliff Owen/AP)

Mr Nadler said on Friday that he expects to issue a subpoena within “a couple of hours” for the full report, including the normally secret grand jury evidence.

That would be likely to spark a lengthy legal and political battle over whether the material can be released.

The report included an account of how the president attempted to seize control of the investigation into Russian interference in the 2016 US election and force out Mr Mueller from leading the inquiry.

But that did not stop Mr Trump from taking a public victory lap on Thursday, declaring at a White House event that he was having “a good day” and insisting that the investigation was politically motivated.

Republicans are eager to push past what Mr Trump calls a “witch hunt” that has overshadowed the party and the presidency.

While Democrats say Mr Mueller’s findings are far more serious than initially indicated in Mr Barr’s four-page summary, they have been hesitant to pursue the ultimate step, impeachment proceedings, despite pressure from the left flank of the party to begin efforts to try to remove the president.

House speaker Nancy Pelosi, speaking during a visit to Northern Ireland, said in a joint statement with Senate Democratic leader Chuck Schumer that Mr Mueller’s report revealed more than was known about the obstruction question.

“As we continue to review the report, one thing is clear: attorney general Barr presented a conclusion that the president did not obstruct justice while Mueller’s report appears to undercut that finding,” they said.

Later, in a letter to House Democrats, Ms Pelosi vowed: “Congress will not be silent.”

Democrats are putting the focus on their next investigative steps. Mr Nadler summoned Mr Mueller to testify and the chairman said he will be issuing subpoenas for the full report. Next week, the House and the Senate are scheduled to hear from Mr Barr, who Democrats accuse of distorting the report’s contents to Mr Trump’s benefit.

Mr Mueller laid out multiple episodes in which Mr Trump directed others to influence or curtail the Russia investigation after the special counsel’s appointment in May 2017, and Mr Trump made clear that he viewed the probe as a potential mortal blow — “the end of my presidency”.