John Bolton flabbergasted Mulvaney wants to join his lawsuit -- because he was part of Trump's Ukraine scandal

White House acting chief of staff Mick Mulvaney attempted to avoid testifying before Congress this week when he joined a lawsuit brought by John Bolton's former deputy Charles Kupperman. The lawsuit is asking the courts to determine which takes precedence: a Congressional subpoena or a White House's demand not to comply with the subpoena.

According to the Washington Post, some close to Bolton and Kupperman said that both men "were flabbergasted" that Mulvaney wanted to join the lawsuit "because they and others on the national security team considered Mulvaney a critical player in the effort to get the Ukrainian government to pursue investigations into Trump's political opponents."

Bolton reportedly sees Mulvaney as someone actively participating in Trump's campaign to pressure witnesses from testifying about the Ukraine scandal. The former Director of National Intelligence once called the scandal as "a drug deal" and Trump's lawyer Rudy Giuliani "a drug dealer," his previous aides testified.

White House officials said that Bolton and Mulvaney weren't even speaking when Bolton left.

Mulvaney's lawyer, William Pittard, told The Post that Mulvaney is trying to reconcile the separation of powers the White House has fought.

"As acting chief of staff, Mr. Mulvaney intends to follow any lawful order of the president and has no reason to think that the order at issue is unlawful — other than the fact the House has threatened him with charges of contempt and obstruction for following it," Pittard told The Post.

The report cited Laurence Tribe, a constitutional law expert, who said that Mulvaney is likely trying to "shield" himself "from having to obey his legal duty to comply with an obviously valid subpoena."

Read the full report from The Washington Post.