A senior US lawmaker apologized Wednesday to BP chief Tony Hayward for what he described as a White House “shakedown” that led the firm to create a 20-billion-dollar Gulf of Mexico oil spill fund.

“I’m ashamed of what happened in the White House yesterday,” Republican Representative Joe Barton told Hayward as the embattled energy giant’s top executive faced his first public grilling by angry US lawmakers.

“There is no question that BP is liable for the damages, but we have a due process system where we go through litigation and court cases to determine what the damages are and when they should be paid,” Mr. Barton said.

“I apologize,” said the Texas representative. “It is a tragedy of the first proportion that a private corporation can be subjected to what I would characterize as a shakedown, in this case, a 20-billion-dollar shakedown.”

His remarks about the fund, meant to pay for environmental and economic devastation from the worst ecological catastrophe in US history, drew immediate condemnation from White House press secretary Robert Gibbs.

“What is shameful is that Joe Barton seems to have more concern for big corporations that caused this disaster than the fishermen, small business owners and communities whose lives have been devastated,” said Gibbs.

“Congressman Barton may think that a fund to compensate these Americans is a ‘tragedy,’ but most Americans know that the real tragedy is what the men and women of the Gulf Coast are going through right now. Members from both parties should repudiate his comments,” Gibbs said in a statement.