The former special counsel, Robert S. Mueller III, made his first public comments last month about the investigation he led for about two years. Credit: Doug Mills/The New York Times

WASHINGTON — Robert S. Mueller III, the former special counsel, has agreed to testify in public before Congress next month about his investigation into Russia’s election interference and possible obstruction of justice by President Trump, House Democrats announced on Tuesday night.

Coming nearly three months after the release of Mr. Mueller’s report, two back-to-back hearings on July 17 before the House Judiciary and Intelligence Committees promise to be among the most closely watched spectacles of Mr. Trump’s presidency. They have the power to potentially reshape the political landscape around his re-election campaign and a possible impeachment inquiry by the Democrat-controlled House.

Mr. Mueller, a strait-laced former F.B.I. director who has spoken publicly only once about his work as special counsel, had resisted taking the witness stand. He knows he is certain to face questions from both sides of a pitched political fight. Many Democrats are eager to employ him to build a case against Mr. Trump, and Republicans are just as eager to vindicate the president. His 448-page written report, Mr. Mueller asserted, should speak for itself.

In the end, though, the two committees issued subpoenas compelling Mr. Mueller to speak, and he accepted.

The chairmen of the panels, Representatives Jerrold Nadler of New York and Adam B. Schiff of California, wrote in a letter to Mr. Mueller on Tuesday that they understood that he had reservations about appearing on Capitol Hill, but they were insistent he do so, anyway.

“The American public deserves to hear directly from you about your investigation and conclusions,” the chairmen wrote. “We will work with you to address legitimate concerns about preserving the integrity of your work, but we expect that you will appear before our committees as scheduled.”

The White House declined to comment on Tuesday night. However, Mr. Trump posted a familiar two-word refrain on Twitter amid news of the testimony: “Presidential Harassment!”

The president and his attorney general, William P. Barr, have said that they have no issue with Mr. Mueller testifying, but they could theoretically try to block him from appearing, as they have other former government officials.

Representative Adam B. Schiff of California on Tuesday in Washington. He and Representative Jerrold Nadler of New York sent a letter to Mr. Mueller insisting he appear on Capitol Hill. Credit: Michael A. McCoy for The New York Times

The stakes could scarcely be higher for Mr. Trump, who is facing re-election next year, or for Congress, which is battling to weaken him. The executive and legislative branches have been locked in an ever escalating dispute over access to documents and witnesses related to Mr. Mueller’s work, with the White House refusing to honor congressional subpoenas and court battles looming. That intransigence has prompted growing calls for an impeachment inquiry on Capitol Hill, but has also slowly lost the attention of the wider public.

The hearings will most likely be aired live and in full on network and cable television. With other potential witnesses off limits for now, Mr. Mueller possesses perhaps the singular authority to shift the dynamic in Washington and change the minds of Americans across the country who long since cast their lot with Mr. Trump or his critics.

Full story at https://www.nytimes.com/2019/06/25/us/politics/robert-mueller-testify.html