Guardian: BP chief executive Tony Hayward will appear before the US house energy and commerce subcommittee on oversight and investigations at 10am EST (3pm BST) to answer questions on the Deepwater Horizon oil spill. This is his prepared testimony, released before the hearing: Chairman Stupak, ranking member Burgess, members of the subcommittee. I am Tony Hayward, chief executive of BP plc. The explosion and fire aboard the Deepwater Horizon and the resulting oil spill in the Gulf of …