The Justice Department says ample evidence supports a federal judge's decision that BP acted recklessly in the lead-up to the 2010 Gulf of Mexico oil spill, and the judge should deny BP's request for a new trial.

In a response to BP's efforts to unravel U.S. District Judge Carl Barbier's 153-page ruling that the spill resulted from gross negligence, the federal prosecutors argue that BP had waived its objections to key evidence that the oil company now claims Barbier should not have considered.

That evidence played prominently in the judge's finding Sept. 4 that BP, owner of the Macondo subsea well, was grossly negligent, a ruling that raises the stakes for the London-based oil major. If the judge later sides with prosecutors on how much oil spilled into the Gulf, BP could face $18 billion in pollution fines.

Earlier this month, BP argued that Barbier erred by considering testimony from petroleum engineer Gene Beck, an expert witness for Halliburton, the cement contractor on the Macondo project.

He testified in a trial earlier this year that production casing - pipe linking the reservoir to the wellhead - hit the bottom of the well with such force when it was inserted that it was weakened and later gave way.

The well blew out, destroying the Deepwater Horizon drilling rig, killing 11 workers and spilling millions of barrels of oil into the ocean.

BP said it had objected at trial to that testimony because it wasn't included in a report Beck submitted, and that Barbier sustained the objection.

But the Justice Department attorneys wrote in court documents this week that at the trial in New Orleans last year, BP's attorney brought up the testimony in a cross examination, waiving the company's objections.

In separate court documents filed Thursday, Halliburton made the same argument. "BP itself explored the bases for Dr. Beck's opinion," Halliburton lawyers wrote.

Even excluding that testimony, the federal prosecutors said, remaining evidence supports the court's conclusion that mistakes by BP were key factors that led to the well blowout and the oil spill.

In his ruling, Barbier said a series of errors led to the spill, including drilling beyond what was deemed safe and misreading pressure tests. The accumulation of those mistakes, Barbier said, meant BP was grossly negligent in the days before the spill.

"Indeed, removal of one disputed point of testimony would affect at most only a few sentences" in the ruling, the federal prosecutors wrote, adding the only testimony that was excluded was the use of certain data to specify the force that caused the casing to buckle.

"BP had many chances to move to exclude Dr. Beck's testimony regarding a casing breach, and indeed had the opportunity to call a witness to rebut it, but did not do so," the Justice Department attorneys wrote. "It is too late now."

In earlier court documents, the oil company said more of the blame for the disaster should be apportioned to Houston-based Halliburton.

Barbier ruled BP bears two-thirds of the fault for the spill, while rig contractor Transocean, which owned the doomed Deepwater Horizon, was 30 percent responsible and Halliburton was 3 percent to blame.

BP has set aside $42 bil-lion to pay for oil spill costs, and has paid some $28 billion for cleanup efforts and fines, penalties and compensation. Barbier's ruling that BP was grossly negligent means the company may owe up to $18 billion in Clean Water Act fines. A third, penalty phase of the trial will begin in January.