Two U.S. SEC commissioners broke with their colleagues because of what they see as overly forgiving treatment of financial wrongdoers. Released Wednesday, their sharply worded letter reveals a growing rift in the Securities and Exchange Commission between those tending to grant leniency to financial firms and a small contingent demanding a stricter approach.

The dissenting commissioners faulted an official order that would release the embattled investment bank Oppenheimer & Co. Inc. from punitive measures. Last week, the firm paid $20 million in penalties to the SEC and Treasury Department over illegal sales of billions of shares of penny stocks on behalf of clients. Along with the fines, the Oppenheimer Holdings Inc. unit faced a so-called Bad Actor disqualification, automatically barring the firm from certain trading activities.

Oppenheimer submitted a request in December asking to have that disqualification waived, allowing it to continue normal operations. The SEC granted the request on the condition that the firm retain a law firm to review its practices and undertake a training program.

Commissioners Luis A. Aguilar and Kara M. Stein dissented, citing Oppenheimer’s “long and unfortunate history of regulatory failures ... cumulatively indicative of a wholly failed compliance culture.” Since 2005, Oppenheimer has faced more than 30 regulatory actions, the commissioners said in their letter.

Aguilar and Stein took particular umbrage at the waiver’s condition that the investment bank hire lawyers to scrutinize its practices, a requirement they found insufficiently rigorous. “There is no legally enforceable requirement that the law firm hired to review Oppenheimer’s policies and procedures for ensuring compliance ... will be qualified and independent,” the commissioners said.

“Given the firm’s recidivism,” Aguilar and Stein said, “we should not blindly rely on what is essentially just another unconvincing promise to do better.”

The Oppenheimer case does not represent the first time either Aguilar or Stein has blasted the SEC for going easy on culprits. Last August, Aguilar broke ranks with the commission over a settlement it offered to an financial executive accused of fraud. Calling terms of the settlement “a wrist slap at best,” Aguilar wrote, “This case is emblematic of a broader trend at the commission where fraud charges ... are warranted, but instead are downgraded.”

Earlier in 2014, Stein dissented from an order that released Royal Bank of Scotland Group PLC from automatic penalties relating to its criminal conviction in the massive case centered on the fixing of the London interbank offered rate, aka Libor. The SEC’s accommodations “implicate a structural problem with our policy, whether dealing with criminal or civil misconduct,” she contended.

Stein added, “I fear that the commission’s action to waive our own automatic disqualification provisions may have enshrined a new policy -- that some firms are just too big to bar.”