US Attorney General Merrick Garland has appointed a special counsel to oversee the Justice Department’s ongoing criminal investigation into President Joe Biden’s son over his taxes, a major development after a controversial plea deal reached by Hunter Biden fell apart in court last month.

Garland has named US Attorney David Weiss — the official already overseeing the politically fraught probe — as the special counsel, a decision that will remove Weiss from day-to-day oversight of Biden administration officials.

The appointment came just as prosecutors revealed in court that plea talks with Hunter Biden had reached an “impasse.” They told a judge that they believed the tax charges could not “resolve short of a trial.”

Announcing the move on Friday, Garland cited the “extraordinary circumstances” of the ongoing investigation into an immediate family member of the sitting president. Weiss will become the third special counsel appointed by Garland. Jack Smith is leading an investigation into former President Donald Trump, and Robert Hur is exploring President Biden’s handling of classified material.

The probe into Hunter Biden began in 2018 amid suspicion over taxes related to his extensive foreign business dealings. The president’s son ultimately struck a deal to plead guilty to two misdemeanor tax crimes. He would have to admit that despite efforts by his accountant to prepare his tax documents and “profligate spending,” he failed for years to pay taxes.

Weiss had been confirmed to the US attorney post in Delaware under Trump and agreed to stay on under Biden. Garland made clear on Friday that Weiss would have sweeping powers, including the authority to investigate any matters that may arise during the course of the investigation, just as congressional Republicans ramp up claims that suspect business dealings potentially include payments made to other Biden family members and even President Joe Biden.

Neither the White House nor Hunter Biden’s team were given advance notice that Garland was going to appoint a special counsel, according to a person familiar with the matter. A White House spokesperson declined to comment.

Garland has the power to remove Weiss, but must show cause to do so. Weiss will continue to serve as the US attorney in Delaware.

House Speaker Kevin McCarthy in a tweet questioned how Weiss could be “trusted as a Special Counsel” if he “negotiated the sweetheart deal that couldn’t be approved.” He vowed his party would continue its investigations. Trump released a statement calling on Weiss to investigate President Biden along with his son.

The deal had aimed to cap a five-year investigation into Biden’s tax affairs and business dealings that culminated with federal prosecutors alleging he failed to pay more than $1,00,000 in income tax on at least $1.5 million in income he received in 2017 and 2018. The deal also would have allowed Hunter Biden to avoid prison on a separate charge for possessing a gun while addicted to an illegal drug.

At the July 26 hearing, however, US District Judge Maryellen Noreika had refused to sign off on it, expressing concerns about the structure of the agreement and the scope of what it could mean for any future charges.

Noreika entered an order on Friday giving Hunter Biden’s lawyers until noon local time on