Four White House officials are expected not to appear Monday to testify before House committees conducting the impeachment inquiry into President Trump, according to a report.

The four are acting at the direction of the White House, the Wall Street Journal reported.

Trump and congressional Republicans have slammed the inquiry as a “witch hunt” and criticized Democrats for a lack of transparency by having witnesses testify behind closed doors in a basement room on Capitol Hill.

Robert Blair, senior adviser to acting White House Chief of Staff Mick Mulvaney, John Eisenberg, a lawyer on the National Security Council, Michael Ellis, a deputy to Eisenberg, and Brian McCormack, an associate director at the White House Office of Management and Budget, were all scheduled to appear.

Blair’s lawyer, Whit Ellerman, told CNN that his client is “caught between the assertions of legal duty by two coequal branches of government, a conflict which he cannot resolve.”

Congressional investigators want to grill Blair about Trump’s pausing nearly $400 million in military aid to Ukraine to pressure the country’s leader to investigate Joe Biden, a Democratic presidential candidate.

Blair, who listened in on the July 25 conversation between Trump and President Volodymyr Zelensky, told the Office of Management and Budget that Trump had directed Mulvaney to hold up the military funds.

Mulvaney is also director of the budget office.

The July phone call, which was revealed in a whistleblower’s complaint, is at the heart of the impeachment inquiry launched in September by House Speaker Nancy Pelosi.

Eisenberg was expected to be questioned about the concerns raised by other national security officials about the call, including those expressed to him by Lt. Col. Alexander Vindman.

The White House has said it would not cooperate with the inquiry and has been telling former and current administration officials not to appear.

But some have defied the White House and testified voluntarily.

The House last Thursday moved to formalize the impeachment inquiry and lay out the ground rules to make it more transparent.

All but two Democrats voted for the resolution, while all Republicans opposed it.