Democrats ask White House's Mick Mulvaney to testify

House Democrats on Tuesday called on White House Chief of Staff Mick Mulvaney to testify in an impeachment probe into President Donald Trump's dealing into Ukraine.

"Based on evidence gathered in the impeachment inquiry and public reporting, we believe that you possess substantial first-hand knowledge and information relevant to the House’s impeachment inquiry,” the chairs of the House Intelligence, Foreign Affairs and Government Oversight committees wrote in a letter to Mulvaney.

House Intelligence Chairman Adam Schiff, House Foreign Affairs Chairman Eliot Engel and acting House Oversight Chairwoman Carolyn Maloney said Mulvaney "may have been directly involved in an effort" that would benefit Trump’s personal political interests.

Mulvaney is requested to appear at a deposition Friday, but the White House said repeatedly it would not comply with the probe.

Citing Mulvaney’s news briefing at the White House on Oct. 17, the Democrats said the acting chief of staff "admitted publicly" that Trump held up security aid to press Ukraine for Trump's "personal, political interests, rather than the national interest."

The Democrats called Mulvaney’s statements as "nothing less than a televised confession" that Trump ordered to freeze the aid on his behalf.

House Democrats launched an impeachment inquiry against Trump on Sept. 24 following claims by a whistle-blower that the president sought to pressure Ukraine to interfere in the 2020 presidential elections.

In a July 25 telephone call Trump allegedly made $400 million military aid contingent on Ukrainian President Volodymyr Zelensky launching a probe into former U.S. Vice President Joe Biden, and his son, Hunter, a businessman, over unsubstantiated corruption allegations.

The elder Biden is a leading candidate in the race for the Democratic nomination to challenge Trump for the presidency in 2020. Trump, a Republican, has accused Democrats of time-wasting and says the inquiry amounts to a “lynching.”