WASHINGTON — The White House is denying a request by the chairman of the House Oversight and Government Reform Committee to have senior adviser Stephen Miller testify about the administration's contentious immigration actions.

"The precedent for members of the White House staff to decline invitations to testify before congressional committees has been consistently adhered to by administrations of both political parties and is based on clearly established constitutional doctrines,” White House counsel Pat Cipollone wrote in a letter Wednesday to the committee's chairman, Rep. Elijah Cummings, D-Md.

Cipollone referred to a letter that President Barack Obama’s White House counsel, Robert Bauer, wrote to then-Oversight Chairman Darrell Issa, R-Calif., in 2011, that stated, “White House staff generally do not testify before Congress.”

He also referred to a letter to Congress in 1980 from the White House counsel at the time, Lloyd Cutler, that said, “Congress has always respected the privilege of the president to decline requests that the president himself or his immediate White House advisers appear to testify before congressional committees."

Cipollone did write, however, that having executive branch officials testify "would be a reasonable accommodation to the Committee's questions and legislative goals."

Cummings sent a letter to Miller last week requesting that he testify before his committee about President Donald Trump’s immigration agenda, including the "zero tolerance" policy that led to family separations at the border, a proposal to bus asylum seekers to sanctuary cities, and recent upheaval at the Department of Homeland Security.

After getting Cipollone’s response, Cummings, along with House Homeland Security Committee Chairman Bennie Thompson, D-Miss., and House Judiciary Committee Chairman Jerrold Nadler, D-N.Y., wrote the acting director of the Department of Homeland Security, Kevin McAleenan, on Thursday seeking documents related to Trump’s recent removal of several senior leaders at the Homeland Security Department.

Earlier this month, Trump announced that Homeland Security Secretary Kirstjen Nielsen and other department leaders were leaving their posts, with a report in The Washington Post saying Trump wanted to move in a "tougher direction" on immigration enforcement and was giving Miller more influence over immigration and border issues.

“We are deeply concerned that the firing and forced resignation of these officials puts the security of the American people at risk,” the Democratic chairmen wrote. “We are also concerned that the President may have removed DHS officials because they refused his demands to violate federal immigration law and judicial orders. Moreover, we are concerned by reports that, even as he has removed the Department’s leadership, the President has sought to empower a White House aide, Stephen Miller, to ‘be in charge of handling all immigration and border affairs.’”

Trump said in an interview with the Post on Tuesday that he is opposed to current and former White House officials testifying before congressional committees in the wake of special counsel Robert Mueller’s report, heightening a confrontation between his administration and House Democrats as they probe the findings of the report.

“There is no reason to go any further, and especially in Congress where it’s very partisan — obviously very partisan,” Trump told the newspaper.