The Trump administration and acting Consumer Financial Protection Bureau chief Mick Mulvaney won round one in a legal battle challenging Mulvaney's leadership. His critics will have a tall order trying to win round two.

The lawyer for CFPB Deputy Director Leandra English, who claims she is the rightful acting director, will face off against the Justice Department in a court hearing where key questions about the CFPB's independence and the president's authority to appoint an interim director are sure to be raised.

English is still a long shot to unseat Mulvaney — as evidenced by the judge's denial last month of English's request to have Mulvaney immediately removed. But the oral arguments could delve into questions over Mulvaney's early moves as CFPB director, including a freeze on new regulations and his decision to bring more political appointees into the agency, which critics say threaten the CFPB's independence.

Read more in American Banker.