President Donald Trump responds to questions about the U.S. House impeachment investigation during a formal signing ceremony for the U.S.-Japan Trade Agreement at the White House in Washington, October 7, 2019.Kevin Lamarque | ReutersThe White House said Tuesday that it will not cooperate with House Democrats’ impeachment inquiry into President Donald Trump, claiming that the proceedings amount to “baseless, unconstitutional efforts to overturn the democratic process.””You have designed and implemented your inquiry in a manner that violates fundamental fairness and constitutionally mandated due process,” White House counsel Pat Cipollone said in an eight-page letter to House Speaker Nancy Pelosi, House Intelligence Chairman Adam Schiff, Oversight Chairman Elijah Cummings and Foreign Affairs Chairman Eliot Engel.Read the full letter here or scroll down.”Put simply, you seek to overturn the results of the 2016 election and deprive the American people of the President they have freely chosen,” Cipollone added. He also accused the Democratic leaders of viewing the impeachment inquiry as “a strategy to influence the next election” in 2020. “Your highly partisan and unconstitutional effort threatens grave and lasting damage to our democratic institutions, to our system of free elections, and to the American people,” Cipollone wrote.Dozens of Democrats were spurred to support an impeachment inquiry after learning of damning allegations in a whistleblower’s complaint, which accused Trump of “using the power of his office to solicit interference from a foreign country in the 2020 U.S. election.That complaint focused mainly on Trump’s July 25 phone call with Ukraine President Volodymyr Zelensky, a partial transcript of which was released by the White House late last month. In that call, Trump asked Ukraine to “look into” unsubstantiated corruption allegations against former Vice President Joe Biden — a frontrunner in the Democratic presidential primary — and his son, Hunter.Trump also asked Zelensky to “do us a favor though” and investigate matters related to the Russia probe concluded earlier this year by former special counsel Robert Mueller, after the Ukraine leader said his administration was “almost ready to buy more [Javelin missiles] from the United States for defense purposes.”That exchange, and the White House’s decision to delay hundreds of millions of dollars in military aid to Ukraine, have raised suspicions among Democrats that Trump was trying to pressure a foreign leader to investigate his potential political opponents. That aid, which was delayed for months without a clear explanation, was ultimately given to Ukraine last month.Cipollone’s defiant letter came hours after the White House blocked a key witness in the impeachment probe from testifying behind closed doors before the House panels. The State Department directed that official, U.S. ambassador to the European Union Gordon Sondland, not to show up for the meeting.Schiff called the Trump administration’s moves “acts of obstruction of a coequal branch of government,” and added that Sondland had also been blocked from sharing documents in his possession related to the inquiry.The Democratic leaders said later Tuesday that they would issue a subpoena for Sondland’s testimony and documents.In a statement, White House press secretary Stephanie Grisham said, “The President has done nothing wrong, and the Democrats know it.””These partisan proceedings are an affront to the Constitution — as they are being held behind closed doors and deny the President the right to call witnesses, to cross-examine witnesses, to have access to evidence, and many other basic rights,” Grisham said.Read the full letter below:This story is developing. Please check back for updates.