WASHINGTON — Four witnesses who were scheduled to testify Monday in the House impeachment inquiry skipped their closed-door depositions.

The four witnesses in the Ukraine case who were scheduled to testify included John Eisenberg, deputy counsel to the president for national security affairs and legal adviser to the National Security Council; Robert Blair, assistant to the president and senior adviser to the acting chief of staff; Michael Ellis, senior associate counsel to the president and deputy legal adviser to the National Security Council; and Brian McCormack, associate director for natural resources, energy and science at the Office of Management and Budget.

All four witnesses had been subpoenaed to appear and testify.

House Democrats had previously said that they would forgo court battles with defiant witnesses and instead consider their efforts to stonewall lawmakers as grounds for a separate article of impeachment on obstruction of Congress. Democrats say they have not yet decided, however, whether to pursue impeachment of President Donald Trump.

Concerns about the July 25 call between Trump and Ukraine’s president by the whistleblower were communicated to the White House, specifically Eisenberg, who along with the CIA’s general counsel told the top national security lawyer at the Justice Department, John Demers, that the allegations should be examined by the DOJ.

Several witnesses who have already testified in the impeachment inquiry told lawmakers that they consulted Eisenberg about the phone conversation. Ellis was Eisenberg’s deputy and part of the discussion about how to handle the transcript of the phone call, according to The New York Times.

According to The Washington Post, Blair was on the July 25 phone call between the two leaders in which Trump asked his Ukrainian counterpart for his country to investigate former Vice President Joe Biden, who could potentially be his 2020 presidential opponent in the general election.

McCormack is the former chief of staff to Energy Secretary Rick Perry, who was subpoenaed to testify in the inquiry, but isn’t expected to appear, reports said.