The U.S. presidential commission investigating the massive oil spill in the Gulf of Mexico found no instance where a decision deliberately sacrificed safety to cut costs, says the chief counsel to the inquiry.

"To date, we have not seen a single instance where a human being made a conscious decision to favour dollars over safety," Fred H. Bartlit Jr. said.

Fred Bartlit Jr., chief counsel to the U.S. commission investigating the BP Deepwater Horizon oil spill, talks about some of his findings at a hearing in Washington on Monday. (J. Scott Applewhite/Associated Press)

Daniel Becnel, a Louisiana lawyer suing BP and others over the oil spill, called the commission's findings about money not jeopardizing safety "absolutely absurd."

He also took issue with Bartlit's endorsement of BP's view of events.

"They are pasting over because they know the government is going to be a defendant sooner or later in this litigation," Becnel said.

According to testimony before the government's joint investigative panel, the Macondo well project was nearly $60 million over budget days before the explosion. That panel has been paying particular attention to the issue of whether money was put ahead of safety.

Bartlit's view also conflicted with allegations by Democrats in Congress who accused BP of cutting corners when it made several critical well-design decisions.

Democrats accused BP of cutting corners

Those decisions have also been questioned by other major oil companies.

In a June letter to then-BP CEO Tony Hayward, Democratic congressmen Henry Waxman and Bart Stupak, questioned at least five decisions BP made in the days leading up to the explosion.

"The common feature of these five decisions is that they posed a trade-off between cost and well safety," said Waxman and Stupak.

"Time after time, it appears that BP made decisions that increased the risk of a blowout to save the company time or expense," the lawmakers wrote.

On April 20, an explosion on the Deepwater Horizon drilling rig 66 kilometres off the Louisiana coast killed 11 workers and led to the largest accidental release of oil — five million barrels — into marine waters in history.

Bartlit said he agreed with about 90 per cent of BP's findings on the disaster, although there were some areas where the inquiry's findings conflicted.

A BP report found flaws with contractor Halliburton's cement job and maintenance performed by rig owner Transocean Ltd.

The company's report has been criticized as self-serving and a preview of its legal case.

The commission has not yet released its final report. Bartlit said the findings he will present are not meant to assign blame or liability but to get to the root cause "without a lot of bickering and self-serving statements."

With files from The Associated Press