Image source, Reuters

Robert Mueller answered a total of 112 questions with one-word answers in his testimony this morning, according to a tally by CBS News, the BBC's US affiliate.

Mueller's monosyllabic approach is consistent with his approach since the probe began - the former special counsel wants his exhaustive report to speak for itself.

Mueller corrects himself from this morning.

Guidelines issued by the Department of Justice's Office of Legal Counsel (OLC) state that a sitting president cannot be indicted.

"I want to go back to one thing that was said this morning by Mr Lieu... 'you didn't charge the president because of the OLC opinion'.

"That is not the correct way to say it... we did not reach a determination as to whether the president committed a crime."

"I am not making any judgments or offering any opinions about the guilt or innocence in any pending case," Mueller says.

"Given my role as a prosecutor there are reason why my testimony will necessarily be limited."

He's unable to talk about the opening of the Russia investigation or matters about the Steele dossier, he says.

The president has tweeted again about today's hearings.

"I understand that this committee has a unique jurisdiction," says Mueller, referring the intelligence committee's counter-intelligence purview.

He points out that his office did not make any "counter-intelligence conclusions".

Rather, they passed along any counter-intelligence information uncovered to FBI investigators, he says.

Mueller and his assistant, Aaron Zebley, have both been sworn in.

Nunes says it's "highly unusual" for Zebley to be sworn in as they're here to ask Mueller questions.

"The Democrats colluded with Russian sources to develop the Steele Dossier," says Nunes, throwing the claim of collusion across the aisle at his Democratic colleagues.

He says that Glenn Simpson, the head of Fusion GPS (the company that commissioned the report), worked with Russian politicians to craft the dossier.

"it's time for the curtain to close on the Russian hoax. The conspiracy theory is dead," he concludes.

Jay Sekulow, counsel to President Trump, said in a statement: "This morning’s testimony exposed the troubling deficiencies of the Special Counsel’s investigation.

"The testimony revealed that this probe was conducted by a small group of politically-biased prosecutors who, as hard as they tried, were unable to establish either obstruction, conspiracy, or collusion between the Trump campaign and Russia.

"It is also clear that the Special Counsel conducted his two-year investigation unimpeded. The American people understand that this issue is over. They also understand that the case is closed."

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California Republican Congressman Devin Nunes (above, right) calls today's hearing "the last gasp of the Russia collusion conspiracy theory".

He blames Democrats for attempting to "foist this spectacle on the American people," by feeding information to "naive and partisan reporters".

Nunes worked with the Trump team during his transition to the White House, and is considered a close ally of Trump.

He said the Mueller inquiry was "marred by corruption and bizarre abuses" by Mueller's team, who "wanted to stop Trump from being elected".

Anthony Zurcher
BBC North America reporter

Image source, Getty Images

During his public appearance in May announcing the end of his special counsel inquiry, Robert Mueller said he didn't want or need to testify before Congress on the results of his investigation.

On Wednesday, it was clear why he felt that way.

The Justice Department publicly issued guidelines on Tuesday that set boundaries on Mr Mueller's testimony, instructing him to stay within the confines of the written report.

So here's what we've seen so far.

Opening the session, House intelligence committee chairman Adam Schiff, a California democrat, calls Mueller's report "methodical and devastating".

He describes how the Trump campaign did not disclose Russian efforts to contact his campaign, including during a 2016 Trump Tower meeting in New York.

Schiff continues to say that although there is no "provable crime" committed, there may have been "something worse" that occurred.

He characterises the "greed and corruption" from a campaign "willing to do whatever it takes to win" including lying about connections to Moscow.

He calls Trump "a candidate trying to make more money than all of them, through a real estate project that to him, was worth a fortune, hundreds of millions of dollars, and the realisation of a lifelong ambition - a Trump Tower in the heart of Moscow".

He accuses Trump and cohort of "his disloyalty to country".

The House Intelligence Committee has begun its hearing. The committee has allotted two hours to question Mueller.

Like before, each member gets five minutes to ask what they will.

The focus of this hearing is expected to be on the evidence of Russian interference and Trump campaign links to Russia during the election, like through Wikileaks.

According to BBC partner CBS News, the Intelligence Committee has said it does not believe Mueller needs to stay within the four corners of the report in his responses.

The BBC's North America Bureau Chief Paul Danahar says today's hearing has raised the slight possibility that Trump could face charges after leaving the White House.

Press Secretary Stephanie Grisham has commented on the hearing.

"Mueller's team specifically informed the committees that he would decline to read from his report during the hearing," according to reports in US media.

By declining to read from his own report, Mueller is denying Democrats and Republicans any sound bites that can be used in attack ads in the 2020 presidential campaign.

At one point, a Democratic lawmaker tried to goad Mueller into reading a passage, only to have the veteran prosecutor say that he'd prefer the lawmaker himself read it to the committee.

Doug Collins, the ranking Republican on the House Judiciary Committee penned an op-ed in the New York Times released on the morning of Mueller's testimony, calling on his colleagues across the aisle to "move on from Robert Mueller", external.

Collins skewered Democrats for wasting time and taxpayer money on "empty investigations".

Despite Mueller's "supersize" investigation - 2,800 subpoenas, nearly 500 search warrants, and 500 witnesses - Democrats have failed to make a viable case for impeachment as part of "their vendetta against the White House", Collins said.

"They’ve wasted six months trying to establish a conspiracy even the special counsel’s team couldn’t find," the Republican said. "Now their only hope is that Mr. Mueller will go rogue on C-Span."

"The Mueller report has been public since April," Collins wrote. "It's time to accept it."

Mueller largely stuck to the script: his own exhaustive report into Russian meddling.

But Mueller refused to speak beyond the bounds of his probe, often responding to questions outside his 448 page report with "that is outside my purview".

Some US commentators say the Democrats may have miscalculated by calling on the former special counsel to testify.

In many ways, the president's potential impeachment is the elephant in the room for Mueller.

Some Democrats called Mueller's report an "impeachment referral".

Republicans, on the other hand, insist the special counsel's probe serves as an exoneration for the president. And commentators are divided on whether Mueller is helping or hurting Democrats' chances of moving an impeachment inquiry forward.

Even among the American public, support for impeachment may be waning.

The latest NBC News/Wall Street Journal poll, external shows that just 21% of Americans want to begin impeachment proceedings, down from 27% in June.

• Mueller says he could not charge Trump with a crime, even if he had found sufficient evidence, due to a longstanding Department of Justice policy of not charging a sitting president with a crime
• Trump could theoretically be charged after leaving office
• He disputed Trump's claim of "total exoneration" saying that Trump "was not exculpated" by his report
• Mueller said he would "generally agree" that lies from Trump staff members "impeded" his investigation
• He denied for the first time Trump's claim that he had applied to be FBI director, but agreed that he had discussed the role with Trump, but not as a candidate

Next up: the House Intelligence Committee will get their turn to question the former special counsel.

The second hearing is expected to begin around 12:30, Washington time. It's half an hour later than scheduled as the Judiciary's hearing ran long.

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