Barr, who has already criticized Mueller's investigation of Russian election interference, possible Kremlin coordination with the Trump campaign and possible obstruction by President Donald Trump, squeezed in yet another shot at Mueller in the closing moments of the hearing.

"Why should you have them?" he asked.

In the final exchange of his hourslong testimony before the Senate Judiciary Committee on Wednesday, Barr told Sen. Richard Blumenthal, D-Conn., that "no," he would not provide those notes to the panel.

Attorney General William Barr refused to turn over notes of the phone call he had with Robert Mueller after the special counsel complained about Barr's summary of the Russia probe's findings.

Mueller's letter in late March to Barr, which complained about how the summary of the Russia report's conclusions had been characterized, was "a bit snitty" and was "probably written by one of his staff people," Barr said.

That letter, which is signed by Mueller, complained that Barr's initial four-page summary of principal conclusions from the 448-page Russia report distorted its "context, nature, and substance" and had caused "public confusion about critical aspects of the results" of the 22-month probe.

A spokesman for the special counsel declined to comment on whether Mueller or a member of his staff had written the letter to Barr.

The attorney general had said in his opening statement of the Senate hearing that when he called Mueller after receiving the letter, the special counsel assured him that the summary was not inaccurate, but rather that "the press reporting had been inaccurate and that the press was reading too much into it."

Mueller's letter, which Barr received less than a week after the Russia report was submitted on March 22 but was not publicly revealed until Tuesday, intensified Democrats' calls for the special counsel himself to testify.

An increasing number of Democrats, including multiple presidential candidates, called on Barr to resign before he had even finished testifying.

Sen. Kamala Harris, D-Calif., objected to Barr's admission that he and Deputy Attorney General Rod Rosenstein had not personally reviewed the raw evidence that formed the basis for the special counsel's report.

Sen. Cory Booker, D-N.J., another 2020 candidate, tweeted after the hearing that "it's become clear that he lied to us and mishandled the Mueller report. He needs to step down."

Booker TWEET

In his summary to congressional Judiciary committee leaders — sent just days after Mueller delivered the report to the Justice Department — Barr said the Mueller report found that neither Trump nor anyone associated with his 2016 campaign coordinated with the Kremlin.

Barr also wrote that while Mueller's report says it "does not exonerate" Trump on the question of whether he obstructed justice, Barr and Rosenstein determined that the evidence was "not sufficient" to establish an obstruction offense.

Mueller's letter said that Barr's summary of the conclusions "threatens to undermine a central purpose for which the Department appointed the Special Counsel: to assure full public confidence in the outcome of the investigations."

Read Mueller's letter to the attorney general