"Imagine that four of the prosecutors separated themselves from the case when the President did that [intervened] just days after firing Lieutenant Colonel Vindman for speaking truth to power. This all must be investigated," Pelosi said.
Trump says said he never spoke to anyone at the Justice Department about the Stone case while using Twitter to express outrage that prosecutors recommended Stone serve seven to nine years and praising US Attorney General William Barr for his decision to seek a lighter sentence.
Stone was convicted by a jury in November of obstructing Congress and witness tampering as part of the Special Counsel Robert Mueller investigation into allegations of Trump-Russia collusion.
Trump removed Vindman from the White House National Security Council (NSC) last week after the latter testified in the House of Representatives impeachment inquiry.
In his testimony, Vindman acknowledged reporting to his superiors that Trump’s request for a Ukrainian investigation of former Vice President Joe Biden for corruption was possibly illegal.