A federal appeals court ruling striking down the leadership structure of the Consumer Financial Protection Bureau as unconstitutional is being seen by critics as a rebuke of U.S. Sen. Elizabeth Warren's signature project—the agency she conceived and set up in the wake of the 2008 financial crisis.

A three-judge panel of the D.C. Circuit Court of Appeals ruled yesterday that the bureau's leadership—with a director appointed to a five-year term and immune from presidential removal—was unconstitutional.

"The CFPB has been, and will remain, highly accountable to both Congress and the President, and continued Republican efforts to transform the agency's structure or funding should be seen for what they are: attempts fostered by big banks to cripple an agency that has already forced them to return over $11 billion to customers who have been cheated," Warren said in a statement.

The ruling was cheered as a victory by the banking industry and business groups — and lamented by the White House and consumer protection advocates.

"It really is probably the greatest rebuke that we have seen to date of the CFPB's approach to regulation," said Scott Pearson, partner in the Los Angeles office of Ballard Spahr, which represents clients before the agency. "The court indicated that the CFPB was basically out of control."

CFPB spokeswoman Moira Vahey said the bureau is considering options for appeal.