As he prepares for his Senate confirmation hearing on Thursday, acting interior secretary David Bernhardt has come under pressure from House Democrats to explain his unusual method of keeping records of his meetings with his own staffers and those who have business before the agency.

The lawmakers are examining Interior’s practice of preparing “a daily card” with Bernhardt’s detailed schedule on a Google document but withholding that information from the public. The detailed accounting of the acting secretary’s meetings is prepared the evening before or at the start of the morning; the document is later overwritten to reflect his appointments for the following day. The public gets to see none of this.

Bernhardt’s practice is a departure from that of his predecessors, who kept more-detailed calendars that identified those with whom they were meeting and when, and made the information available to the public on the agency’s website.

The acting secretary’s meetings are of keen interest to lawmakers and watchdog groups because his work history as an oil lobbyist and as a representative for large Western water agencies has the potential to create serious conflicts of interest at an agency that controls drilling rights and access to water.

Democrats on the Senate Energy and Natural Resources Committee plan to make the availability of Bernhardt’s detailed calendar a central part of their questioning at his confirmation hearing Thursday, along with topics such as climate change, public lands management and endangered species protections.

Bernhardt, who joined Interior as its number-two official in August 2017, has been running the department since Jan. 2, after Ryan Zinke stepped down in the face of multiple ethics probes. Having served on Capitol Hill, in the George W. Bush administration and private sector, Bernhardt has used his familiarity with Interior’s inner workings to advance energy development and reverse several conservation measures adopted under President Barack Obama.

The existence of his cards came to light in November in the course of a public-records request by a researcher. Two months later, Freedom of Information Act officers at Interior informed him that staffers had to take a tedious step to fulfill his request: They had to go back and look at version histories of the same Google document, which changed every workday, dating back for months because it had been overwritten.

Bernhardt’s staff does periodically release a daily calendar listing of those with whom he meets, but unlike other secretaries, it has not identified the specific purpose of internal staff sessions. He began disclosing the topics of meetings with outside groups in January, at the request of House Natural Resources Committee Chairman Raúl M. Grijalva (D-Ariz.).

When Grijalva pressed the issue and requested Bernhardt’s personal calendar, the acting secretary fired off a letter on Feb. 28. “I have not personally maintained a calendar for years, and I have no intention of suddenly doing so now,” he wrote. Bernhardt then challenged the congressman to publicly disclose his own meetings with nongovernmental groups, writing, “Together, our leadership on this issue will provide a good example.”

Interior eventually shared hundreds of versions of Bernhardt’s daily card as part of 7,137 documents the department submitted to Grijalva’s committee late Monday.

On the same day, Cole Rojewski, the director of Interior’s Office of Congressional and Legislative Affairs, submitted a letter defending Bernhardt’s actions, saying the department’s legal counsel had confirmed that Bernhardt’s office was in compliance with its obligations under the Federal Records Act.

“The operations of the Office of the Secretary and the Deputy Secretary involve compiling and managing an ever changing schedule,” Rojewski wrote.

Grijalva’s spokesman, Adam Sarvana, confirmed that the panel received the documents but declined to comment further.

The documents, which run 26,792 pages, include the acting secretary’s calendar that Interior has posted publicly; proposal forms that external groups submit for meetings; and a daily schedule included in the acting secretary’s nightly briefing book.

At a budget hearing Wednesday, Grijalva asked a top Interior appointee to explain a March 14 email from a senior official — whose name was blacked out — instructing that any correspondence destined for him or any senator should “NOT be sent until you have further direction.” Noting that Trump nominated Bernhardt the next day, Grijalva asked, “Do you know why the email was sent?”

“I have no idea, sir,” replied Scott Cameron, Interior’s principal deputy assistant secretary for policy, management and budget.

The concern over Bernhardt’s transparency has extended beyond the House Natural Resources Committee.

In a hearing this month, the chairman of the House Committee on Oversight and Reform, Rep. Elijah E. Cummings (D-Md.), asked a top Interior official handling Freedom of Information Act requests whether Bernhardt’s record-keeping had raised issues.

“Is the calendar for the acting secretary deleted at the end of each day? Do you know that?” Cummings asked Rachel Spector, the acting deputy chief FOIA officer.

“I don’t know that,” Spector replied, before adding, “I have some familiarity with the issue that you’re raising, and understand that the solicitor’s office in the department is working with the records officer in the department to determine what’s occurred there, and whether it’s consistent.”

Aaron Weiss, the deputy director at the advocacy group Center for Western Priorities, said in a telephone interview that the fact that officials overwrote a version of Bernhardt’s schedule every day is problematic, given the acting secretary’s previous extensive lobbying. Bernhardt has had to recuse himself until August from “particular matters” directly affecting 22 former clients to comply with the president’s ethics pledge.

“It shows just how far David Bernhardt is willing to go to shield his daily activities from the American people,” Weiss said, adding that given the limited information on the acting secretary’s public calendar, “they are taking an entirely ‘take my word for it’ approach to David Bernhardt’s conflicts.”