Former national security adviser John Bolton was 'so alarmed' by efforts to encourage Ukraine to investigate the Bidens and 2016 election meddling that he told an aide, Fiona Hill, to alert White House lawyers, according to the New York Times.

On Monday, Hill told House investigators that Bolton got into a heated confrontation on July 10 with Trump's EU ambassador, Gordon D. Sondland, who was working with Trump attorney Rudy Giuliani to investigate Democrats. Hill said that Bolton told her to notify the top attorney for the National Security Council about the 'rogue' effort by Sondland, Giuliani and acting White House chief of staff Mick Mulvaney.

"I am not part of whatever drug deal Sondland and Mulvaney are cooking up," Bolton apparently told Hill to tell the lawyers.

It was not the first time Mr. Bolton expressed grave concerns to Ms. Hill about the campaign being run by Mr. Giuliani. “Giuliani’s a hand grenade who’s going to blow everybody up,” Ms. Hill quoted Mr. Bolton as saying during an earlier conversation. The testimony revealed in a powerful way just how divisive Mr. Giuliani’s efforts to extract damaging information about Democrats from Ukraine on President Trump’s behalf were within the White House. Ms. Hill, the senior director for European and Russian affairs, testified that Mr. Giuliani and his allies circumvented the usual national security process to run their own foreign policy efforts, leaving the president’s official advisers aware of the rogue operation yet powerless to stop it. -NYT

When Hill confronted Sondland, he told her that he was 'in charge' of Ukraine, "a moment she compared to Secretary of State Alexander M. Haig Jr.’s declaration that he was in charge after the Ronald Reagan assassination attempt, according to those who heard the testimony," according to the Times.

Hill says she asked Sondland on whose authority he was in charge of Ukraine, to which he replied 'the president.' She would later leave her post shortly before a July 25 phone call with Ukraine's president which is currently at the heart of an impeachment inquiry.

Meanwhile, the Times also notes that "House Democrats widened their net in the fast-paced inquiry by summoning Michael McKinley, a senior adviser to Secretary of State Mike Pompeo who abruptly resigned last week, to testify Wednesday."

Career diplomats have expressed outrage at the unceremonious removal of Ambassador Marie L. Yovanovitch from Ukraine after she came under attack by Mr. Giuliani, Donald Trump Jr. and two associates who have since been arrested on charges of campaign violations. The interviews indicated that House Democrats were proceeding full tilt with their inquiry despite the administration’s declaration last week that it would refuse to cooperate with what it called an invalid and unconstitutional impeachment effort. -NYT

Three other Trump admin officials are scheduled to speak with House investigators this week, including Sondland - who is now set to appear on Thursday. On Tuesday, deputy assistant secretary of state George Kent will testify, while on Friday, Laura K. Cooper - a a deputy assistant secretary of defense for Russia, Ukraine and Eurasia policy, will speak with lawmakers as well.