House Speaker Nancy Pelosi on Tuesday said President Trump is “obstructing Congress from getting the facts” it needs in the impeachment inquiry after his administration blocked a US diplomat from testifying before three committees.

She added that Trump’s behavior is “an abuse of power” — and “that is one of the reasons that we have an impeachment inquiry” related to the president’s dealings with Ukraine.

Her comments came hours after Team Trump barred US Ambassador to the European Union Gordon Sondland from appearing before the House Foreign Affairs, Intelligence and Oversight committees.

“There will be a subpoena issued for him to come testify,” Pelosi said.

“Our Constitution, the genius of it, is a system of checks and balances that we would have three separate co-equal branches of the government that would have checks and balances on the other,” she told reporters in Seattle.

“The president said Article 2 says, ‘I can do whatever I want.’ No, it doesn’t, Mr. President. So he’s snubbing his nose at the vision of our founders, his disloyalty to the Constitution is something we have to study.”

The speaker also stressed the importance of protecting whistleblowers.

“The intelligence community respects the role of whistleblowers,” she said. “We all do, but in intelligence, protecting the whistleblower is absolutely essential so that there’s no retribution or anything for speaking truth.”

The impeachment inquiry is focused on a whistleblower’s allegations that Trump used nearly $400 million in US military aid to secure a promise from Ukrainian President Vlodomyr Zelensky to investigate former Vice President Joe Biden, who leads the field of Trump’s potential challengers, and his son Hunter.

Sondland — a Trump donor who started his diplomatic role in July — said he hoped “the issues raised by the State Department that preclude [my] testimony will be resolved promptly.”

“He stands ready to testify on short notice, whenever he is permitted to appear,” Sondland’s lawyer, Robert Luskin, said in a statement.

Trump has denied he did anything wrong in a July 25 phone call with Zelensky in which Trump pushed for an investigation of the Bidens.

“I would love to send Ambassador Sondland, a really good man and great American, to testify, but unfortunately he would be testifying before a totally compromised kangaroo court, where Republicans’ rights have been taken away, and true facts are not allowed out for the public. … to see,” Trump wrote on Twitter.

Pelosi announced a formal impeachment inquiry last month following the allegations that Trump pressured Zelensky to investigate the Bidens while withholding the military aid.

Sondland’s appearance would have followed officials, including the former US special envoy for Ukraine, Kurt Volker, and Michael Atkinson, the inspector general of the US intelligence community.

Former Ambassador to Ukraine Marie Yovanovitch — whom Trump recalled in May before her term was up after his supporters questioned her loyalty — is scheduled to meet with the committees behind closed doors Friday.

With Post wires