Wells Fargo employees who review customer complaints and workplace issues have voted to unionize. The move is the latest in a campaign to organize workers at the San Francisco-based bank, which is notable in an industry that historically has had low rates of unionization.

A group of conduct management investigators spread across the country voted to join Wells Fargo Workers United. The National Labor Relations Board certified the vote Tuesday.

The unionization push by members of the bank's conduct management intake team has been hotly contested. If approved, it would represent a landmark in the effort to organize workers at the $1.9 trillion-asset bank.