White House on Tuesday announced that it would no longer comply with the impeachment inquiry of President Donald Trump which was initiated by Speaker Nancy Pelosi calling it an illegitimate and unconstitutional process. The eight-page letter by counsel Pat Cipollone has brought a new Constitutional crisis in a war between the White House and the Democrats.

The White House in an open declaration told House Speaker Nancy Pelosi and the chairmen of three congressional panels leading the inquiry, to proceed with their effort to oust Trump despite zero future cooperation. “As you know, you have designed and implemented your inquiry in a manner that violates fundamental fairness and constitutionally mandated due process,” says the letter.

“Put simply, you seek to overturn the results of the 2016 election and deprive the American people of the president they have freely chosen,” White House counsel Pat Cipollone wrote in an eight-page letter.

“Your inquiry lacks any legitimate constitutional foundation, any pretense of fairness, or even the most elementary due process protections,” he said of the probe, which is weighing whether Trump abused his office by seeking a quid pro quo from Ukraine. “President Trump cannot permit his administration to participate in this partisan inquiry under these circumstances.”

Reacting to White House Top Democrat Nancy Pelosi on Tuesday accused the White House of an “unlawful attempt to hide the facts” after it ruled out cooperating with an impeachment probe of President Donald Trump.

Pelosi, the House Speaker, fired back after the White House sent her a letter blasting the impeachment process as partisan, illegitimate and unconstitutional.

“This letter is manifestly wrong, and is simply another unlawful attempt to hide the facts of the Trump Administration’s brazen efforts to pressure foreign powers to intervene in the 2020 elections,” Pelosi said in a statement.

Pelosi formally launched the impeachment inquiry last month after revelations Trump pressured Ukraine’s President Volodymyr Zelensky in a July 25 phone call. Biden, the former vice president who is seeking the 2020 Democratic nomination, joined the chorus of condemnation, tweeting that Trump “must stop stonewalling Congress.”

Chairman of House Permanent Select Committee on Intelligence Adam Schiff, has also accused President Trump of stonewalling the investigation by preventing a key witness in the Ukraine scandal from appearing before the Congress.  Sondland, a major donor to Trump’s 2016 presidential campaign, was one of a handful of US diplomats on a text message chain between July and September that goes to the heart of the investigation. The messages involving Trump’s personal lawyer Rudy Giuliani show them coordinating to pressure Kiev into investigating Biden, as Ukraine sought US military aid and access.

Schiff said investigators have learned that Sondland has text messages or emails on a personal device that are “deeply relevant” to the probe, but that State is withholding them. “The failure to produce this witness, the failure to produce these documents” was “additional strong evidence of obstruction,” Schiff told reporters.

Lawmakers have an opportunity on Friday to hear from another key witness in the Ukraine scandal, former US ambassador to Kiev Marie Yovanovitch, who is scheduled to appear before the House Intelligence Committee. US media has reported that Trump removed her from her post because she opposed his efforts to get Ukraine to investigate Biden.

It was unclear whether Trump will block Yovanovitch’s testimony.

Following the White House’s letter, members of the Trump administration will not be authorized to testify in Congress and will ignore subpoenas, a senior administration official told reporters. He insisted that the White House was “definitely avoiding saying there’s no way we’d ever cooperate,” but he declined to discuss “hypothetical situations” in which a change might come.