Former Vice President Joe Biden on Tuesday sharply criticized President Donald Trump for failing to “put national interest before personal interest,” and said the president is giving Congress “no choice” but to launch an expected impeachment proceeding.

“If we allow a president to get away with shredding the United States Constitution, that will last forever,” Biden said in a brief statement in Wilmington, Delaware. “Too many people have taken an oath and given their lives … to let that happen.

“This isn’t a Democratic issue or a Republican issue,” Biden said, calling on the president and White House to “stop stonewalling” and turn over a whistleblower complaint and other information to lawmakers.

Biden spoke about 90 minutes before Pelosi was expected to announce an impeachment inquiry, a  move that followed a growing number of moderate members of her caucus moving from undecided or against impeachment to supporting it.

They see Trump having tried to use a nearly $300 million military aid package, which he acknowledged earlier in the day he held up for weeks — but blaming Europe for doing so — in an attempt to garner a personal political benefit. The president also has acknowledged discussing Joe Biden’s work to oust what many Western countries agreed was a corrupt Ukrainian prosecutor and his son Hunter Biden’s work for a Ukrainian energy firm that same prosecutor was investigating with the country’s then-president elect in July.

[McConnell demurs on how Senate would handle impeachment articles]

No entity in either country has found any wrongdoing by the former vice president or his son.

Biden calls claims ‘baseless’

Biden called Trump’s claims that he used his influence as vice president to get that prosecutor terminated to help his son “baseless and untrue and without merit.”

“That’s not about to stop him,” Biden said, referring to the president. “That’s what he does. That’s what he’s always done.”

Biden said Congress should use its authority under the Constitution to “demand the information it has a legal right to receive,” and that Trump continues to “flout the law.”

If he does, the president will give House Democrats “no choice but to initiate impeachment,” Biden said, adding such a move would be a “tragedy — but a tragedy of his own making.”

Agreeing with a foreign government to help influence a U.S. election, or merely asking for one, could rise to the level of a criminal offense, legal experts say. House Democrats agree, and are zeroing in on Trump’s alleged request of the new Ukrainian president, who refused to launch a probe of the two Bidens.

“There is no requirement there be a quid-pro-quo in the conversation,” Pelosi said Tuesday, adding she was unsure if the president understands that.

[Pelosi on impeachment: ‘Now that we have the facts, we’re ready — for later today’]

Trump essentially has admitted discussing the former vice president and Hunter Biden with Volodymyr Zelensky when he was Ukraine’s president-elect in late July.

Democrats are accusing the president of misusing his power by holding up the taxpayer-funded assistance to garner a personal political benefit of possibly harming Biden’s chances of securing the Democratic nomination. Numerous public opinion polls show Biden leading Trump nationally and in key battleground states, though Trump’s campaign and analysts say such surveys are not reliable this far out from the election.

“That is self evident that it is not right,” Pelosi said. “We don’t ask foreign governments to help us in our elections. That’s what we tried to stop with Russia. It’s wrong.”

Trump: ‘No pressure’

Biden and Pelosi spoke hours after the president arrived at a U.N. General Assembly session in New York City and again flatly denied pressuring Zelensky.

“There was no quid pro quo,” he told reporters. “There was no pressure applied, nothing.”

Trump announced the White House on Wednesday will release a “complete, fully declassified and unredacted transcript” of the July telephone conversation with now-Ukrainian President Zelensky. In a tweet from the U.N., he claimed it will show “very friendly and totally appropriate call” that featured “No pressure” to investigate the Bidens” and “NO quid pro quo!”

Meantime, House Intelligence Chairman Adam Schiff of California said his panel expects to hear directly from the whistleblower, who he said wants to speak to lawmakers.

Trump fired off a tweet just before Biden spoke, between events at U.N. General Assembly sessions, signaling an impeachment process could further slow work on major legislation.

“The Democrats are so focused on hurting the Republican Party and the President that they are unable to get anything done because of it, including legislation on gun safety, lowering of prescription drug prices, infrastructure, etc. So bad for our Country!” he wrote.

Moments after Biden left the stage, Trump dismissed signs House Democrats were ready to launch an impeachment process, telling reporters at the U.N., “Listen, it’s just a continuation of the witch hunt.”

“Our country’s doing the best it’s ever done,” he said, repeating his standard refrain about the health of the economy. “They’re going to lose the election,” he said of Democrats.

The president then suggested getting impeached months before voters will decide if he gets a second term might help him.

“They say it’s a positive for me,” Trump said, then wondered aloud: “How can you do this and you haven’t even seen the phone call?”