(Bloomberg) -- Special Counsel Robert Mueller agreed to testify publicly before two House panels, setting up a dramatic hearing that promises to reinvigorate the national debate over his findings on Russian election interference and possible obstruction of justice by President Donald Trump.Judiciary Chairman Jerrold Nadler and Intelligence Chairman Adam Schiff, both Democrats, announced the July 17 joint hearing on the eve of Wednesday’s first Democratic presidential debate, where several of the candidates on the Miami stage are likely to remind viewers that they support an impeachment inquiry of the president.The chairmen said that Mueller, who issued his report in April, would appear in an open session and that he had agreed to the appearance under subpoenas.The session, sure to be televised live, sets up one of the most dramatic hearings of the Trump presidency -- and a confrontation between Democrats who have been pursuing investigations of the president since they took control of the House and Trump’s Republican supporters who dismissed the inquiries as fishing expeditions.Until now, the White House has stymied investigations by Nadler, Schiff and other House Democratic chairmen by refusing to let present and former officials appear.Mueller said in his report that he couldn’t conclude whether Trump’s 2016 campaign conspired with Russia and also couldn’t exonerate the president from attempting to obstruct the investigation.Trump has repeatedly denounced the inquiry and steadfastly denied any wrongdoing. The president has tweeted in the past that “after total exoneration by Robert Mueller & the Mueller Report,” Democrats “want a Do Over.”“It never ends,” Trump said Wednesday in an interview with Fox Business Network’s Maria Bartiromo. “We had no obstruction. We had no collusion.”Trump also said Mueller “obviously wasn’t a Trump fan.”Soon after the Mueller hearing was announced, his Twitter post contained just two words: “Presidential Harassment!”Nadler on Wednesday declined to say whether there will be White House lawyers in the room during the Mueller hearing. Nadler acknowledged the possibility that the Trump administration could seek to intervene or block the hearing."They may attempt to,” Nadler said. “I doubt they will succeed because Mr. Mueller is an honest man and understands that congressional subpoenas are not optional."Lawmakers from both parties are likely to tread carefully in their questioning of Mueller, a former FBI director, federal prosecutor and decorated Vietnam War veteran with a reputation for scrupulousness. He has said next to nothing about his investigation beyond the report, and made it clear that he’d prefer to say no more.“Americans have demanded to hear directly from the special counsel so they can understand what he and his team examined, uncovered, and determined about Russia’s attack on our democracy, the Trump campaign’s acceptance and use of that help, and President Trump and his associates’ obstruction of the investigation into that attack,” Schiff and Nadler said in a statement.In a letter accompanying the subpoenas, the chairmen tell Mueller that they understood that there were “certain sensitivities” associated with his testifying in public, including criminal investigations, some of which are continuing. That may indicate that they weren’t ruling out closed-door questioning on some matters.“You have also explained that you prefer for the Special Counsel’s Office’s written work to speak for itself,” they added. “Nevertheless, the American public deserves to hear directly from you about your investigation and conclusions,” they write, saying they will work with Mueller to address his legitimate concerns.The announcement comes after Republicans have taunted Nadler for not producing Mueller for a public hearing sooner.One of Trump’s closest congressional allies, conservative Freedom Caucus Chairman Mark Meadows of North Carolina, warned on Fox News, “Bob Mueller had better be prepared because he will be cross-examined and the American people will see the flaws in his report.”But next month’s hearing carries risks for both parties.Some Democrats have taken comments by Mueller as a virtual invitation to open impeachment proceedings, a course that House Speaker Nancy Pelosi has resisted so far and has said could result in a political backlash because the Republican-controlled Senate would be unlikely to follow up by removing Trump from office.Mueller has said Justice Department rules prohibit the indictment of the nation’s chief executive, and “the Constitution requires a process other than the criminal justice system to formally accuse a sitting president of wrongdoing.”Now, Mueller will be available to directly answer whether impeachment proceedings are what he’s suggesting. If he says that, it will be difficult for Pelosi to continue putting off demands to move forward.For Republicans, their gamesmanship in heckling Democrats for not subpoenaing Mueller to this point could come home to roost. Their claims that Democrats have misinterpreted Mueller’s findings could be proven false.At a Judiciary hearing in April, after the release of the Mueller report, the top Republican on the Judiciary Committee, Doug Collins of Georgia, chastised Nadler and Democrats for not having produced Mueller as a witness.Collins said that absent an impeachment inquiry, calling Mueller himself to testify would be the best way to learn about his findings — and that the hearing should be held.The timing of the scheduled testimony comes a week before the House is set to break for a six-week summer recess, and members are not scheduled to return to Washington until early September.(Updates with Nadler comments beginning in the eleventh paragraph.)To contact the reporters on this story: John Harney in Washington at jharney2@bloomberg.net;Billy House in Washington at bhouse5@bloomberg.netTo contact the editors responsible for this story: Kevin Whitelaw at kwhitelaw@bloomberg.net, Wendy BenjaminsonFor more articles like this, please visit us at bloomberg.com©2019 Bloomberg L.P.