The incident reveals not only the level of confidence with which Wells Fargo’s executives operated, but also the drastic changes the consumer protection agency has undergone under President Trump. The bureau opened in 2011, a chief component of the Dodd-Frank financial regulatory law, and quickly became one of Wall Street’s most feared regulators. It pursued enforcement actions against hundreds of companies and extracted $12 billion in financial relief for nearly 30 million consumers.

But the agency acquired more political overtones after Mr. Trump appointed Mick Mulvaney, a longtime critic of the bureau who once described it as a “sick, sad” joke, to temporarily lead the agency from November 2017 to December 2018. Mr. Mulvaney, now Mr. Trump’s acting chief of staff, installed a new layer of political appointees to head each department and pressed the agency in an industry-friendly direction, focused on deregulation. (All of the bureau’s divisions, including supervision and enforcement, had previously been led by career employees.)

The bureau’s current director, Kathleen Kraninger, has further curtailed the agency’s powers and gutted some of its major regulations, including planned restrictions on payday lending. She has also softened its enforcement actions, settling many cases with little or no financial penalty.

The House report also said that Wells Fargo had dragged its feet on fixing internal controls and that in the spring of 2017, its senior leaders displayed a cavalier attitude toward the tasks that lay ahead of them. The bank’s chief risk officer, Michael Loughlin, wrote to its chief executive at the time, Timothy J. Sloan, proposing a plan to pledge $200 million to customers harmed by the fake accounts and give them just six months to seek reimbursement, the report said. Customers who didn’t step forward in time would be out of luck.

Mr. Loughlin then laid out a plan for what to do with any money that remained: “We promise to give it to charity,” he wrote in an email to Mr. Sloan — but only if the regulators freed them from regulatory constraints imposed in the wake of the sales scandal. “If they do not, no donation. Put the onus back on them.”

The report also said Mr. Sloan gave “inaccurate and misleading” testimony to Congress last year about the bank’s compliance in a matter relating to sales of mortgages and auto loans. Mr. Sloan could not be reached for comment.

Ms. Duke, the board chairwoman, who will testify on Wednesday, also appears in the report. According to the report, she and other board members appeared reluctant to engage with members of the agency’s staff who were trying to ensure that Wells Fargo was making the necessary changes to its management practices to avoid another sales scandal. One staff member wrote to her in July 2017 to express regret that she and another board member had not found time to meet with them over the summer.