House Speaker Nancy Pelosi is pressing for an additional investigation of the Nov. 7 oil spill in the San Francisco Bay.
Pelosi has drafted language for insertion into a budget bill that would force the Department of Homeland Security inspector general to start a new probe.
Separately she is working on a letter to simply request that the DHS inspector general do so.
Pelosi wants the department to investigate the Coast Guard's role in the spill response - not the cause.
The speaker wants this investigation wrapped up by April 1.
Several other probes into the Coast Guard spill response already are underway by the Coast Guard itself, state authorities and a congressional subcommittee.