WASHINGTON, Oct. 8 (Xinhua) -- The White House said Tuesday that it won't cooperate with the ongoing impeachment inquiry into President Donald Trump led by House Democrats.

"You have designed and implemented your inquiry in a manner that violates fundamental fairness and constitutionally mandated due process," White House Counsel Pat Cipollone wrote in a letter to House Speaker Nancy Pelosi, who announced the initiation of the impeachment proceedings on Sept. 24.

The letter was also forwarded to House Intelligence Committee Chairman Adam Schiff, Oversight and Reform Committee Chairman Elijah Cummings and Foreign Affairs Committee Chairman Eliot Engel. They have been leading the now fast-moving impeachment inquiry.

Claiming that the impeachment investigation "violates the Constitution, the rule of law, and every past precedent," Cipollone told the Democratic leaders, "Put simply, you seek to overturn the results of the 2016 election and deprive the American people of the President they have freely chosen."

"President Trump and his Administration cannot participate in your partisan and unconstitutional inquiry under these circumstances," the counsel said.

The Democrats' effort to remove the president stemmed from a whistleblower complaint filed on Aug. 12 alleging that the president pressured his Ukrainian counterpart, Volodymyr Zelensky, during a July 25 phone call to investigate Democratic presidential candidate Joe Biden and his son Hunter Biden, as well as issues related to alleged Russian interference in the 2016 election.

The White House released a rough transcript of the call on Sept. 25, a move claimed by Cipollone as Trump's "unprecedented step of providing the public transparency," adding that the record showed that the call was "completely appropriate and that there is no basis for your inquiry."

Trump requested that Zelensky cooperate with his personal attorney Rudy Giuliani and U.S. Attorney General William Barr to investigate the Bidens, and Zelensky pledged to Trump that his government would specifically look into Burisma Holdings, a Ukrainian gas company for which Hunter Biden once worked and which had been accused of corruption, according to the transcript of the call.

The president also asked his counterpart to do the United States a "favor" by finding out "what happened with" the computer server used by the Democratic National Committee that investigators probing alleged Russian interference in the 2016 U.S. election believed was hacked by Russia. "The server, they say Ukraine has it," Trump told Zelensky, the transcript showed.

The Oversight and Reform Committee, in consultation with the Intelligence and Foreign Affairs committees, issued a subpoena to the White House last Friday, requesting Ukraine-related documents due Oct. 18.

Trump has said he will leave it to his lawyers to decide whether to comply with the subpoena