Kevin McCarthy, left, and Merrick Garland, right
CNN  — 

Speaker Kevin McCarthy is floating the possibility that the House could open an impeachment inquiry into Attorney General Merrick Garland over Internal Revenue Service whistleblower allegations that Justice Department leadership improperly interfered in the Hunter Biden probe, which Garland has denied.

“If it comes true what the IRS whistleblower is saying, we’re going to start impeachment inquiries on the attorney general,” McCarthy said Monday on Fox News.

In congressional testimony publicly released on Thursday, two IRS whistleblowers alleged to lawmakers that the president’s son had been given preferential treatment by the Justice Department.

McCarthy said on Fox News that the IRS agents who came forward “watched the abuse of power in how Hunter Biden was treated.”

The allegation that the DOJ has been politicized against conservatives has been central to how House Republicans approach their congressional investigations, though there is scant evidence backing up most of their claims.

Garland rejected those claim during a Friday news conference.

“Some have chosen to attack the integrity of the Justice Department … by claiming that we do not treat like cases alike,” Garland said. “This constitutes an attack on an instutiton that is essential to American democracy … nothing could be further from the truth.”

Regarding the Hunter Biden probe, the whistleblowers made several explosive allegations, including that the IRS had recommended far more serious charges for the president’s son and that US Attorney in Delaware David Weiss was blocked from bringing charges in other states.

Garland said Friday that Weiss was “permitted to continue his investigation and to make a decision to prosecute any way in which he wanted to and in any district in which he wanted to.”

“I don’t know how it would be possible for anybody to block him from bringing a prosecution, given that he has this authority,” Garland said.

Hunter Biden will plead guilty to two tax misdemeanors and struck a deal with federal prosecutors to resolve a felony gun charge, the Justice Department said Tuesday in court filings.

As part of the plea agreement, the Justice Department has agreed to recommend a sentence of probation for the two counts of failing to pay taxes in a timely matter for the years 2017 and 2018, according to sources. Hunter Biden owed at least $100,000 in federal taxes for 2017, and at least $100,000 in 2018, but did not pay what was due to the IRS by the deadlines.

A judge will have the final say on any sentence.

Garland said Friday he would “support Mr. Weiss explaining or testifying” about the allegations raised by the whistleblowers “when he deems it appropriate.”

McCarthy said on Fox News Monday, “We have requested by July 6, Weiss to come in and answer these questions because the IRS whistleblowers took copious notes.”

The federal prosecutor overseeing the Hunter Biden investigation sent a letter to House Judiciary Chair Jim Jordan in early June saying that he had “ultimate authority” over the probe.

Weiss, who was appointed by former President Donald Trump, makes clear in a letter obtained by CNN that he was granted this authority, cutting against Republican claims that Garland and the DOJ are “weaponized” against conservatives and politicizing the Hunter Biden case.

“I want to make clear that, as the attorney general has stated, I have been granted ultimate authority over this matter, including responsibility for deciding where, when, and whether to file charges and for making decisions necessary to preserve the integrity of the prosecution, consistent with federal law, the Principles of Federal Prosecution, and Departmental regulations” Weiss wrote to Jordan on June 7.

In response, Jordan has asked Weiss to explain and provide further information about the letter stating he had “ultimate authority” over the probe.

Jordan asked in a letter to Weiss why he was the one to respond to Congress on June 7, when the initial letter from Jordan about alleged retaliation against the IRS whistleblowers was addressed to Garland. “Who instructed you to sign and send your June 7 letter to the committee?,” Jordan asked.

Hunter Biden’s lawyer pushed back in a statement on Friday against the whistleblowers’ claims, saying it was “preposterous and deeply irresponsible” to suggest that federal investigators “cut my client any slack” during their “extensive” five-year probe.

CNN’s Annie Grayer contributed.