Robert Mueller has told a congressional hearing that Donald Trump’s claims he was “totally exonerated” by the special counsel report are not true.

Appearing at a highly-anticipated congressional hearing on Wednesday, the former special counsel said he could not clear the president of obstruction of justice.

“The president was not exculpated for the acts that he allegedly committed,” Mueller said at the opening of the hearings into his investigation of Russian interference to help Trump win the 2016 election.

Mueller’s comments mean Trump’s repeated claims of “NO OBSTRUCTION”, the latest made just today, are wide of the mark.

Mueller’s appearance before congressional interrogators opened televised hearings that Democrats hope will weaken US President Donald Trump’s re-election prospects in ways that Mueller’s book-length report did not.

Republicans immediately defended Trump and criticised the Democrats for continuing to go after him.

The back-to-back Capitol Hill appearances, Mueller’s first since wrapping up his two-year Russia probe last spring, carry the extraordinary spectacle of a prosecutor discussing in public a criminal investigation he conducted into a sitting US president.

The first opened with Jerrold Nadler, the Democratic chairman of the House Judiciary Committee, praising Mueller’s career and background.

The hearings come at a moment of deep divisions in Congress and the country, and they raise serious questions about whether Mueller will change anyone’s hardened opinions about impeachment and the future of Trump’s presidency.

Mueller, known for his taciturn nature, has warned that he will not stray beyond what has already been revealed in his report.

And the Justice Department has instructed Mueller to stay strictly within those parameters, giving him a formal directive to point to if he faces questions he does not want to answer.

Trump lashed out early Wednesday ahead of the hearing, saying on Twitter that “Democrats and others” are trying to fabricate a crime and pin it on “a very innocent President”.

“Why didn’t Robert Mueller investigate the investigators?” Trump said in his tweet.

Trump has made Mueller a regular target of attack over the past two years in an attempt to undermine his credibility and portray him as biased and compromised.

Over the last week, Trump began to frequently ask confidants how he thought the hearing would go, and while he expressed no worry that Mueller would reveal anything damaging, he was irritated that the former special counsel was being given the national stage, according to two Republicans close to the White House.

Long aware of the power of televised images, Trump seethed to one adviser that he was annoyed Democrats would be given a tool to ramp up their investigations – and that the cable news networks would now have new footage of Mueller to play endlessly on loop in an effort to embarrass the White House.

Mueller’s approach to testifying may well deny Democrats the made-by-TV moments they want to rally their base.

But Republicans, too, are likely to be left without their sought-after confirmation that the Russia investigation was a politically tainted waste of time.

Trump this week feigned indifference to Mueller’s testimony , telling reporters in the Oval Office on Monday: “I’m not going to be watching – probably – maybe I’ll see a little bit of it.”