BP Exec faces grilling over 'risky shortcuts'

The head of BP in America faces accusations in Congress on Tuesday that the energy giant caused the worst oil spill in US history with a calculated strategy to cut costs.

US law makers will ask BP Plc's US chief, Lamar McKay why the company made repeated choices that appeared to favour cost savings over safety before its rig blew up in the Gulf of Mexico.

McKay will be surrounded at the congressional hearings by executives from Exxon Mobil, Chevron, ConocoPhillips and Royal Dutch Shell seeking to stave off repercussions for the industry.

The explosion in April at an offshore rig killed 11 workers and ruptured BP's well. The spill has fouled 120 miles of US coastline, imperiled multibillion-dollar fishing and tourism industries and killed birds, sea turtles and dolphins.

It comes as President Barack Obama wraps up a two-day trip to the Gulf before returning to Washington to give a televised address to defend his handling of the disaster.

BP has lost more than 40 per cent of its market value since the crisis began and faced a barrage of criticism over its handling of the clean-up.