WASHINGTON — Mick Mulvaney, the interim director of the Consumer Financial Protection Bureau, will move the agency’s student loan division into the bureau’s consumer information unit, a shift that career officials fear will sidetrack a major enforcement case the agency is pursuing against Navient, the nation’s largest student loan collector.

The change, outlined in an email sent to the bureau’s staff Wednesday morning, is part of an effort by Mr. Mulvaney to refocus the agency away from its consumer finance enforcement and rule-writing mission and more toward providing consumers with information about their legal rights.

It follows a similar move Mr. Mulvaney made in February, when he folded the bureau’s fair lending division into the consumer unit, telling staff it would “continue to focus on advocacy, coordination and education.”

Among the bureau’s career staff, the shift was regarded as a new attack on one of the bureau’s core statutory functions, and another attempt by Mr. Mulvaney and his team to dismantle a consumer watchdog reviled by President Trump.