Joe Biden plans to obstruct congress if subpoenaed to testify at President Donald Trump’s impeachment trial in the U.S. Senate.

The former vice president, who claimed for weeks that his appearance at the impeachment proceedings would be a “diversion” to Trump’s benefit, reiterated his position on Friday in conversation with the editorial board of The Des Moines Register in Iowa:

Look, the grounds for them to call me would be overwhelmingly specious. But so I don’t anticipate that happening anyway. But what it would do — if I went, let’s say I voluntarily, just said let me go make my case, what are you going to cover?

He added that appearing at the trial would only shift attention away from the president and the conduct that led to his impeachment.

“You guys, instead of focusing on him, you’re going to cover for three weeks anything I said. And he’s going to get away,” the former vice president said.

The intent to refuse comes as Senate Republicans have signaled it would be inappropriate for an impeachment trial to progress without the former vice president or his youngest son Hunter providing testimony. At the forefront of this push have been Sens. Lindsey Graham (R-SC) and Ron Johnson (R-WI), who have opened investigations into Hunter Biden’s work overseas as to if he benefited from connections to the Obama-era White House.

The controversy started when Trump suggested over the summer that the Ukrainian government investigate Hunter Biden’s ties to Burisma Holdings, an eastern European natural gas company. The younger Biden secured an appointment to the company’s board in May 2014 despite having no background in the energy industry or Ukraine.

More troubling was the fact that Hunter Biden’s appointment, which paid at the time as much as $83,000 per month, seemed to coincide with his father being tapped to lead the Obama administration’s policy in Ukraine in response to Russia’s invasion of Crimea.

As Peter Schweizer detailed in Secret Empires: How the American Political Class Hides Corruption and Enriches Family and Friends, Hunter Biden’s background in banking, lobbying, and hedge fund management paled in comparison to that of current and past members of Burisma’s board.

Adding to concerns was that Hunter Biden joined the company at a time when it was actively courting western leaders to prevent scrutiny of its practices. The same month as the appointment, Mykola Zlochevsky, Burisma’s founder, had his assets frozen in the United Kingdom on suspicion of money laundering. A Ukrainian official with ties to Zlochevsky admitted in October the only reason Hunter Biden secured his position with Burisma was to “protect” the company from foreign scrutiny.

It is in the context of Burisma and Zlochevsky’s legal troubles that Joe Biden’s political influence has raised the most red flags. The former vice president has particularly drawn questions over his conduct in demanding the Ukrainian government fire its top prosecutor, Viktor Shokin, in 2016. Joe Biden, who has publicly bragged about the firing, reportedly threatened to withhold more than $1 billion in U.S. aid if the Ukrainian government did not remove Shokin. He has claimed the demand came from then-President Barack Obama, who had allegedly lost faith in the prosecutor’s ability to tackle corruption.

Unofficially, though, it was known that Shokin was investigating both Burisma and Zlochevsky for public corruption. It is uncertain if the probe extended to Hunter Biden, although Shokin has recently admitted that prior to his ouster, he was warned to back off the matter. Regardless of what occurred, Shokin’s successor, who is now himself being investigated for public corruption, dropped the investigation into Burisma.

Since the start of the impeachment inquiry, all of those potential conflicts of interest have spilled out into the open. Senate Republicans contend that even if Joe Biden and his son did nothing wrong, they should still testify given how muddled the situation has become. Joe Biden, for his part, seems to disagree, foreshadowing a likely standoff between the former vice president and Congress.

On Saturday, Biden slightly walked back his refusal to testify at Trump’s impeachment trial, seeming to imply he was open to cooperating with Congress if he found the proceedings legitimate.

I want to clarify something I said yesterday. In my 40 years in public life, I have always complied with a lawful order and in my eight years as VP, my office — unlike Donald Trump and Mike Pence — cooperated with legitimate congressional oversight requests. — Joe Biden (@JoeBiden) December 28, 2019

But I am just not going to pretend that there is any legal basis for Republican subpoenas for my testimony in the impeachment trial. That is the point I was making yesterday and I reiterate: this impeachment is about Trump’s conduct, not mine. — Joe Biden (@JoeBiden) December 28, 2019

The subpoenas should go to witnesses with testimony to offer to Trump’s shaking down the Ukraine government — they should go to the White House. — Joe Biden (@JoeBiden) December 28, 2019

“In my 40 years in public life, I have always complied with a lawful order and in my eight years as VP, my office — unlike Donald Trump and Mike Pence — cooperated with legitimate congressional oversight requests,” Joe Biden said on social media, before adding there was no reason for him to testify.

“The subpoenas should go to witnesses with testimony to offer to Trump’s shaking down the Ukraine government — they should go to the White House,” he said.