Lawyers who represent victims of General Motors Co.’s ignition switch defects are raising concerns about a planned compensation fund, pushing for punitive damages and questioning who would be eligible.

During a June 18 congressional hearing over GM’s recalls, chief executive officer Mary Barra promised that the fund would not be capped and that people with injuries or deaths predating its 2009 bankruptcy could be eligible. She said GM would begin processing claims on Aug. 1.