The Trump administration, in a significant escalation of its clash with the government's top ethics watchdog, has moved to block an effort to disclose the names of former lobbyists who have been granted waivers to work in the White House or federal agencies.

The latest conflict came in recent days when the White House, in a highly unusual move, sent a letter to Walter M. Shaub Jr., the head of the Office of Government Ethics, asking him to withdraw a request he had sent to every federal agency for copies of the waivers. In the letter, the administration challenged his legal authority to demand the information.

Mr. Shaub returned a scalding, 10-page response to the White House late Monday, unlike just about any correspondence in the history of the office, created after the Nixon Watergate scandal.

"O.G.E. declines your request to suspend its ethics inquiry and reiterates its expectation that agencies will fully comply with its directive," Mr. Shaub wrote in a letter he also sent to every federal agency ethics officer, six members of Congress who oversee government operations and the inspector generals from agencies governmentwide. "Public confidence in the integrity of government decision making demands no less."