WASHINGTON — The Trump White House is moving to paralyze a bipartisan and independent watchdog agency that investigates national security activities that can intrude upon individual rights.

The move comes as the new administration is vowing to put its own stamp on federal law enforcement and intelligence agencies. It also comes ahead of a new conflict over whether or how Congress should renew a warrantless surveillance law that is set to expire in 2026.

Congress established the agency, called the Privacy and Civil Liberties Oversight Board, as an independent unit in the executive branch after the terrorist attacks of Sept. 11, 2001. It has security clearances and subpoena power, and is set up to have five members, appointed by the president and confirmed by the Senate, who serve six-year terms. Some members are picked by the president, and some are selected by congressional leaders of the other party.

It needs at least three members in order to take official actions like starting a new investigative project or issuing a board report with a policy recommendation. Its work has included scrutiny of surveillance and bulk data collection activities as well as terrorism watch lists.

On Tuesday, each of the three members who were picked by Democrats — Edward Felten, Sharon Bradford Franklin and Travis LeBlanc — received an email from the White House telling them to submit resignation letters by the close of business Thursday, according to three people with knowledge of the situation.

The people spoke on condition of anonymity for fear of reprisal. They said the email, sent by Trent Morse, deputy director of presidential personnel, told the board members that President Donald Trump would terminate their positions if they did not resign by that deadline.

The fifth seat is vacant. The White House did not tell the board’s sole current Republican-picked member, Beth Williams, to leave.

The departure of the three Democratic-picked members would mean the agency would lack enough members to function as the Trump administration begins its efforts to reshape the nation’s law enforcement and intelligence agencies.

Sen. Ron Wyden, D-Ore., denounced the move in a statement. “By purging the Democratic members of the Privacy and Civil Liberties Oversight Board, Trump is kneecapping one of the only independent watchdogs over government surveillance who could alert Congress and the public about surveillance abuses by his administration,” he said.