Updated: 5:58 p.m.

Senate Republicans proved Thursday that they have enough votes to filibuster any nominee that President Barack Obama appoints for a consumer protection agency.

In a letter sent to the president, 44 Republicans called for an overhaul of the Consumer Financial Protection Bureau created by last year’s financial regulatory reform bill and pledged to block any nominee tapped to lead the agency absent those changes.

The Senators wrote that the CFPB director has “unprecedented authority over financial institutions” under current law and could threaten to “affect every American household by limiting their choices when purchasing financial products.”

“Despite this broad mandate the Dodd-Frank Act failed to provide any real checks on the CFPB director’s powers,” the Members wrote. “Once confirmed, the director effectively answers to no one.”

The GOP lawmakers are calling on Obama to replace the individual director with a board and give Congress oversight by submitting the agency to the appropriations process.

Sens. Scott Brown (Mass.) and Lisa Murkowski (Alaska) were the only Republican Senators who did not sign on to the letter, which was released by Banking ranking member Richard Shelby (R-Ala.).

The CFPB’s regulatory powers officially kick in in July, and so far Obama has not named anyone to direct the agency. Elizabeth Warren, a Harvard University law professor, has taken the lead in getting the agency off the ground, and she is widely considered by liberals to be the top choice for the full-time job. It remains unclear, however, whether Warren could win Senate confirmation, and Thursday’s letter further complicates the matter.

Shelby urged Obama not to issue a recess appointment to circumvent the confirmation process.

“Senate confirmation is about accountability and giving the American people a voice in the process,” he said. “I would hope the president won’t silence the people’s voice.”