The rare consensus underscores just how little anyone knows, so far, about how any rule might look. Still, even before the details are out, White’s move to insert the agency into the debate has given ammunition to both Wall Street firms and consumer groups in the biggest financial policy battle in Washington.

At issue is an Obama administration effort to stop what it calls biased financial advice that is costing investors billions of dollars. The Labor Department will soon issue a plan to force brokers to adopt afiduciary duty to put retirement clients’ interests ahead of their own. White said she supports imposing a similar standard on all brokers for retail investors.

Lawmakers took their first opportunity on Tuesday to question White about her plans to begin developing a fiduciary duty standard, which she aired for the first time at an out-of-town securities industry conference last week. Those remarks came during a question-and-answer session rather than in a prepared speech, leaving no official text for lawyers and lobbyists to parse back in Washington.