• Hunter Biden declined an invitation to testify in public next week as part of House Republicans' impeachment inquiry into President Joe Biden.
• Abbe Lowell, an attorney for Hunter Biden, told House Oversight Committee Chairman James Comer said that neither he nor his client can attend because of a scheduling conflict with one of Hunter's ongoing criminal cases.
• Hunter Biden sat for a closed-door deposition with the GOP investigators on Feb. 28.

Hunter Biden on Wednesday declined an invitation to testify in public next week as part of House Republicans' impeachment inquiry into President Joe Biden.

Abbe Lowell, an attorney for Hunter Biden, in a letter to House Oversight Committee Chairman James Comer, R-Ky., said that neither he nor his client can attend because of a scheduling conflict with one of Hunter's ongoing criminal cases.

But that's "the least of the issues," said Lowell, who blasted the planned public hearing as an act of desperation by Republicans whose impeachment probe of the Democratic incumbent president has come under increasing scrutiny.

"Your blatant planned-for-media event is not a proper proceeding but an obvious attempt to throw a Hail Mary pass after the game has ended," Lowell wrote.

Comer responded later Wednesday that the Oversight panel "has called Hunter Biden's bluff," and that the hearing will move forward as planned.

"Hunter Biden for months stated he wanted a public hearing, but now that one has been offered alongside his business associates that he worked with for years, he is refusing to come," Comer said in a statement to NBC News.

Hunter Biden sat for a closed-door deposition with the GOP investigators on Feb. 28. In that hourslong interview, he strongly disputed allegations at the center of the impeachment probe that his father was involved in his business dealings.

Comer on March 6 had invited Hunter Biden to testify again on March 20, this time in a public hearing titled, "Influence Peddling: Examining Joe Biden's Abuse of Public Office."

Three of Biden's former business associates, Devon Archer, Tony Bobulinski and Jason Galanis, have also been asked to testify.

That invitation came weeks after federal authorities arrested and charged Alexander Smirnov, a former FBI informant, with lying to the government about Joe and Hunter Biden. Prior to his indictment, the Republican impeachment investigators portrayed Smirnov's allegations as a key piece of their case.

"I thought even you would recognize your baseless impeachment proceeding was dead" in light of "the realization that your inquiry was based on a patchwork of conspiracies spun by convicted liars and a charged Russian spy," Lowell wrote in Wednesday's letter.

"As Mr. Biden said numerous times, backed up by an accurate reference to the records in the Committees' possession, his father was never involved in or derived any financial benefit from Mr. Biden's businesses," Lowell wrote.

The attorney also pointed to an exchange during Hunter Biden's deposition in which Comer suggested he was open to asking about the business activities of Jared Kushner, the son-in-law of former President Donald Trump, as part of the probe's focus on "influence peddling."

"If you are serious about pursuing this oversight purpose in a legitimate and bipartisan fashion, you would hold a hearing with relatives of former President Trump," Lowell wrote.

"If you do, Mr. Biden would consider an invitation for that event."