Oil giant BP faced mounting pressure Monday to control a massive oil slick in the Gulf of Mexico after the US government threatened to take over the response to the month-old disaster.
"If we find that they're not doing what they're supposed to be doing, we'll push them out of the way," said Interior Secretary Ken Salazar.
Salazar insisted that the full force of the federal government was bearing down on BP, which is legally responsible for dealing with a ruptured pipe that has been gushing oil into the gulf from the wreckage of an offshore rig.
The BP-leased Deepwater Horizon rig exploded on April 20, killing 11 workers, and sank two days later. Ever since, hundreds of thousands of gallons of oil, perhaps even millions, have been spewing each day into the sea.
Salazar lashed out at BP for missing "deadline after deadline" as its latest attempt to cap the environmentally devastating leak was hit with further delays, saying the company faced an "existential crisis".
"Do I have confidence that they know exactly what they're doing? No, not completely," he added.
His comments came as President Barack Obama's administration faced growing criticism over its handling of the crisis.
Right-wing darling and former vice presidential candidate Sarah Palin accused Obama of being lax in his response to the disaster and suggested this was because he was too close to the lucrative offshore oil drilling industry.
Louisiana Governor Bobby Jindal demanded urgent action to stop the oil lapping up on beaches and coating fragile coastal wetlands.
He lambasted the US Coast Guard, which is overseeing the response, for failing to deliver and lay out enough protective booms despite repeated requests from local officials.
"We met today to take action, take matters into our own hands," a frustrated Jindal told reporters in the coastal port of Venice.
A local emergency manager commandeered all 40 boom-laying boats hired by BP which were sitting idly at Grand Isle as oil sloshed onto beaches on Saturday night.
Residents and officials in neighboring Plaquemines Parish headed out in their own boats Sunday to lay protective booms around a bird sanctuary, where several birds have already been coated in oil and taken it back to their nests.
Coast Guard Admiral Mary Landry acknowledged that the response had lagged, and told reporters she has called BP to task for failing to make sure boats do not sit idle if there is work to be done.
"There's really no excuse for not having constant activity," Landry said in a conference call.
The slick, meanwhile, has continued to grow.
Initially scheduled to begin on Sunday, BP's latest attempt to plug a leak in the ruptured pipe 5,000 feet (1,500 meters) below the surface is not expected to get under way until Wednesday at the earliest.
Crews used robotic submarines to try to seal it with cement, yet the amount of oil being suctioned up by a mile-long insertion tube slowed to 1,360 barrels a day from the previous average of about 2,100.
"It really depends largely on the mix between oil and gas," BP spokesman Graham MacEwan told AFP. "It's not a constant flow so it will fluctuate over time."
Oil also continues to wash past protective booms, sullying 66 miles (106 km) of Louisiana's coastline and spreading out towards Florida.
The amount of oil still gushing from the rig's wreckage has also been a major point of contention, with BP initially putting the figure at 5,000 barrels, or 210,000 gallons, a day, but experts saying it could be more than 20 times as high.
The cost of the clean-up also continued to mount. BP said in London Monday that the operation had so far cost the company 760 million dollars (607 million euros).
It added that it was "too early to quantify other potential costs and liabilities associated with the incident."