The House Intelligence and House Judiciary committees are preparing to hear public testimony from former special counsel Robert Mueller III, in relation to his two-year FBI investigation into the 2016 presidential election.

Mueller is now scheduled to appear before both committees on July 24, a week later than originally planned. Under a revised agreement, Mueller is expected to testify for three hours before the Judiciary Committee, followed by two hours before the Intelligence Committee.

The extra week gives Mueller more time to prepare, as House Republicans and Democrats both have extensive questions and intend to cross-examine the former FBI director over a number of details included in the 448-page special counsel report.

Democrats view Mueller as the key witness in their multiple investigations into the Trump administration. They hope to reinforce their claim that Trump and his staff criminally obstructed justice at different stages during the Russia probe. Senior Democrats are hoping to use the House committee hearings as a substitute, of sorts, for formal hearings to impeach or censure President Trump.

Republicans, meanwhile, view Mueller’s appearance as an opportunity to publicly examine the origins of the Russia investigation. Given the fact that the FBI found no conspiracy of collusion between the Trump campaign and Russian interests, the question remains as to why the investigation continued on for nearly two years.

There are also questions surrounding the role that members of the intelligence community played in creating the Russia-collusion narrative and whether faulty intelligence led to members of Trump’s campaign team being placed under surveillance by the FBI.

In a joint statement, on Friday, July 12, Judiciary committee Chairman Jerrold Nadler (D-N.Y.) and Intelligence committee Chairman Adam Schiff (D-Calif.), explained, “This will allow the American public to gain further insight into the special counsel’s investigation and the evidence uncovered regarding Russian interference in the 2016 presidential election and President Trump’s possible obstruction of justice and abuse of power.”

President Trump responded to the news that Mueller would be given additional time to testify, by saying, “There’s nothing Mueller can say. He’s written a report. It said no collusion, and it said, effectively, no obstruction. They want to go to it again and again and again because they want to hurt the president before the election.”

In late May, as Mueller stepped down from the role of special counsel, he made clear that any testimony he gives before Congress would not go beyond that of his report.