The unraveling of Hunter Biden's plea agreement has thrust his criminal case into uncertain waters and given new fodder to Republican critics in Congress as they push ahead with investigations into the president's youngest son. Biden was supposed to plead guilty Wednesday to misdemeanor charges for failing to pay taxes. But U.S. District Judge Maryellen Noreika in Delaware put the brakes on the guilty plea after raising concerns during an hourslong hearing about the structure and terms of the agreement and another deal that would allow him to avoid prosecution on a gun charge if he meets certain conditions. Plea deals are carefully negotiated between defense lawyers and prosecutors over the course of weeks or months and it's unusual — especially in high-profile cases — for judges to not sign off on them. But Wednesday's hearing revealed that the two sides apparently did not see eye to eye on the scope of the agreement around a non-prosecution clause for crimes outside of the gun charge. A look at what happens now in the criminal case and what's next for the Biden investigations in Congress: WHAT HAPPENS NOW IN COURT? Noreika — an appointee of former President Donald Trump — told both sides to file written briefs addressing her concerns within 30 days. Among other things, Noreika took issue with a provision in the agreement on the gun charge that she said would have created a role for her where she would determine if he violated the terms. The lawyers said they wanted her to serve as a neutral fact finder in determining if a violation happened, but Noreika said that is the Justice Department's job — not the judge's. Hunter Biden's lawyers and the Justice Department also disagreed on the extent to which the agreement gave him immunity from future prosecution. A prosecutor said Wednesday their investigation was ongoing, and that the agreement protecting him from other potential charges was limited only to certain offenses over a certain time frame. Biden's lawyers said it was broader than that. After intense courtroom negotiations, the two sides appeared to agree to a more narrow non-prosecution clause. Biden's lawyers and prosecutors will now continue negotiations to see if they can salvage the agreement in a way that satisfies the judge. "They are going to have to go back and figure out how they can come to an agreement terms of the plea and they have to come to a meeting of the minds, which is clear they don't have here," said Jessica Tillipman, associate dean for government procurement law studies at George Washington University Law School. "So I think what you'll see is a renewed effort — or it's just going to collapse." The judge may ultimately accept the deal that was proposed or reject it. If the deal totally falls apart, Biden could eventually face a trial. WILL HE AVOID JAIL TIME? Even if the judge ultimately accepts the plea agreement, she will have the final say on whether he serves any time behind bars. Prosecutors have said that they will recommend probation, but the judge can decide not to follow that. The two tax charges carry up to a year in prison. And the judge suggested on Wednesday that it was too soon to say whether she's willing to sign off on probation. “I can’t predict for you today whether that is an appropriate sentence or not,” Noreika said. “I can’t say that I will accept the sentence recommendation or whether a different sentence would be more appropriate.” WHAT'S GOING ON IN CONGRESS? The collapse of the younger Biden’s plea deal Wednesday came as joyful news to House Republicans vying to connect him and his questionable business dealings to his father. Republicans had already slammed the agreement as a “sweetheart deal." “The judge did the obvious thing, they put a pause on the plea deal, so I think that was progress,” Rep. James Comer, the Republican chairman of the House Oversight Committee, said Wednesday. “I think it adds credibility to what we’re doing.” He added that this will only propel their investigation to get answers “as to what the family did, and what level of involvement the president had.” Comer has been investigating Hunter Biden’s financial ties and transactions since gaining the gavel in January. The Kentucky lawmaker has obtained thousands of pages of financial records from various members of the Biden family through subpoenas to the Treasury Department and various financial institutions. Last month, shortly after Hunter Biden reached an agreement with the government, Comer joined forces with two chairmen of powerful committees to launch a larger investigation into claims by two IRS agents who claimed the Justice Department improperly interfered in the yearslong case. IRS supervisory special agent Greg Shapley and a second agent, Joe Ziegler, testified before Congress last week that there was a pattern of “slow-walking investigative steps” into Hunter Biden, including during the Trump administration in the months before the 2020 election that Joe Biden won. One of the most detailed claims was that U.S. Attorney David Weiss in Delaware, the federal prosecutor who led the investigation, asked for special counsel status in order to bring the tax cases against Hunter Biden in jurisdictions outside Delaware, including the District of Columbia and California, but was denied. Weiss and the Justice Department have denied that, saying he had “full authority” and never sought to bring charges in other states. Despite the denials, Republicans are moving forward with their probes, asking Weiss to come in and testify about the case directly. The Justice Department has offered to have the prosecutor come before lawmakers after the August recess. ____ Richer reported from Boston. Read More Ukraine war’s heaviest fight rages in east - follow live Charity boss speaks out over ‘traumatic’ encounter with royal aide White House attacks McCarthy’s impeachment gambit as ‘ridiculous, baseless stunt’ Hunter Biden pleads not guilty to two tax charges after chaos around deal Hunter Biden’s plea deal appears at risk of falling apart. What happens next?