General Motors Co. Chief Executive Mary Barra and General Counsel Mike Millikin have been called to testify next week before a senate subcommittee investigating why it took the company nearly 11 years to recall older small cars equipped with a faulty ignition switch, the Wall Street Journal reported today. The witness list also includes Chicago Attorney Anton Valukas, Delphi Automotive PLC CEO Rodney O'Neal and compensation expert Kenneth Feinberg who is handling payouts to any driver, passenger, pedestrian or occupant of another car hurt or killed in accidents attributed to the faulty ignition switch. The slate of witnesses is the biggest yet and suggests senators will probe the issue much more than their counterparts in the House, which held its hearing last month. Some senators have been critical of an internal investigation conducted by Valukas which cleared Barra and her executive team of any wrong doing while pinning most of the blame on switch designer Ray DeGiorgio.