Last week, it was oil executives who faced the wrath of lawmakers eager to find blame for the massive oil spill spreading in the Gulf of Mexico.
On Tuesday, Interior Secretary Ken Salazar and other federal officials will come under questioning for what the government did -- or did not do -- to prevent the oil spill, and how they have responded since oil started streaming into the Gulf last month.
Salazar, who oversees the federal agency that monitors offshore drilling, will testify before two Senate committees. Environmental Protection Agency Administrator Lisa Jackson and Coast Guard Commandant Thad Allen also will testify at separate hearings, and oil company executives are back for a second round of questions.
The hearings come amid the first high-level resignation related to the oil spill and a decision by President Barack Obama to name a presidential commission to investigate the cause of the rig explosion that unleashed millions of gallons of oil into the Gulf of Mexico, where engineers are struggling after three weeks to stop the flow.
The presidential panel will be similar to ones that examined the Challenger space shuttle disaster and the Three Mile Island nuclear power plant accident, said a White House official, speaking on condition of anonymity because the decision had not been formally announced.
The commission would be one of nearly a dozen investigations and reviews launched since the April 20 explosion, although it probably would be the most comprehensive.
With BP PLC, the company that owns the well, finally gaining some control over the amount of oil spewing into the gulf, scientists are increasingly worried that huge plumes of crude already spilled could get caught in a current that would carry the mess all the way to the Florida Keys and beyond, damaging coral reefs and killing wildlife.
Scientists said the oil will move into the so-called loop current soon if it hasn't already, though they could not say exactly when or how much there would be. Once it is in the loop, it could take 10 days or longer to reach the Keys.
The U.S. Coast Guard reported that 20 tar balls were found off Key West on Monday, but said a lab analysis would have to determine their origin. The Florida Park Service during a shoreline survey found balls that were about 3 to 8 inches in diameter.
Last week, Obama decried what he called a badly failed offshore drilling system and said failures extended to the federal government and its "cozy" relationship with oil companies. The Minerals Management Service, the federal agency that oversees offshore drilling, has long been criticized for being too close to industry.
On Monday, White House press secretary Robert Gibbs said government failures "certainly" include the Obama administration, which took office in January 2009.
"But my guess is you guys did some stories in the previous decade on what was going on at MMS, which is what caused Secretary Salazar, when he came in, to begin reforming that," Gibbs told reporters.
Salazar, anticipating tough questioning on Capitol Hill, announced Monday he is tightening requirements for onshore oil and gas drilling. The new measures would not apply to oil rigs at sea, and Salazar had outlined the broad outlines of the reforms in January.
Even so, he tried to portray them as more evidence of the Obama administration's aggressive response to the Gulf spill.
"The BP oil spill is a stark reminder of how we must continue to push ahead with the reforms we have been working on and which we know are needed," Salazar said in a statement.
Chris Oynes, associate administrator of the minerals agency, became the first administration official to resign in the wake of the oil spill. Oynes, who was regional director in charge of Gulf offshore oil programs for 13 years before being promoted in 2007 to head all offshore drilling programs, informed colleagues he will retire at the end of the month, according to an e-mail obtained by The Associated Press.
Oynes, like other MMS officials, has come under criticism for being too close to the industry.
A 35-year government employee, Oynes had earlier indicated his plans to retire but decided to accelerate his departure, said an administration official who spoke on condition of anonymity because the issue involved a personnel matter. It was unclear what pressure, if any, was put on him.
Members of Congress, meanwhile, were continuing to focus attention on the Gulf spill.
Sen. Barbara Boxer, D-Calif., and seven other senators asked the Justice Department to determine whether BP made false and misleading claims to the government about its ability to prevent a serious oil spill when it applied for permission last year to drill the Deepwater Horizon well that has unleashed environmental havoc along the Gulf coast.
Boxer, who chairs the environment panel, said BP claimed to have the capability to prevent a serious oil spill in case of a well blowout.
"In the wake of the Deepwater Horizon oil spill ... it does not in any way appear there was 'proven equipment and technology' to respond to the spill" as BP claimed, she and the other senators wrote Attorney General Eric Holder. They asked the Justice Department to determine whether any criminal or civil laws may have been violated as far as misleading the government.
In the month since the oil rig exploded, killing 11 workers, BP has struggled to stop the leak, trying in vain to activate emergency valves and lowering a 100-ton box that got clogged with icy crystals. Over the weekend, the oil company finally succeeded in using a stopper-and-tube combination to siphon some of the gushing oil into a tanker, but millions of gallons are already in the Gulf.
AP writers H. Josef Hebert and Erica Werner contributed to this report.