Chastened by heavy criticism from lawmakers, a grim-faced BP chief executive Tony Hayward said Thursday he was "deeply sorry" for his company's catastrophic oil spill in the Gulf of Mexico.

"I understand the seriousness of the situation, the frustrations and fears that continue to be voiced," he told a House investigations subcommittee.

But before testifying, Hayward had to endure more than an hour of mostly unrelenting criticism from Democrats and Republicans alike.

"We are not small people, but we wish to get our lives back," Rep. Bart Stupak, D-Mich., the panel's chairman, told Hayward, throwing back at the oil giant comments made the day before by BP Chairman Carl-Henric Svanberg — about how BP sympathized with the "small people" of the Gulf — and Hayward's earlier remark that he wanted his "life back."