Published: May 11, 2010 11:27 AM EDT

WASHINGTON (AP) - Congress begins hearings today on the massive oil spill threatening sensitive marshes and marine life along the Gulf Coast and the blame game is in high gear.

Executives of the three companies involved in the drilling activities that unleashed the environmental crisis are trying to shift responsibility to each other Testimony prepared for a pair of hearings was obtained by The Associated Press.

Lawmakers are expected to ask BP, which operated the sunken drilling rig, why its drilling plans discounted the risk of a catastrophic pipeline rupture and why it assumed a leak would not pose a major threat.

The morning hearing by the Energy and Natural Resources Committee and the afternoon session before the Environmental and Public Health Committee give lawmakers their first chance to question the executives publicly.