The long-running battle between Ecuadorian plaintiffs and Chevron Corp. lately has been overshadowed by harsh accusations and name calling between the big-firm lawyers in the case.

In dueling briefs filed two days apart last week, attorneys from Patton Boggs, which represents the plaintiffs, and Gibson, Dunn & Crutcher on behalf of Chevron, levied a new round of charges aimed at each other, including allegations of fraud, coercion, tortious interference and “smear tactics.”

In a brief filed on Dec. 12 in the U.S. Court of Appeals for the D.C. Circuit, Patton lawyers say Chevron — and its attorneys with Gibson — have made “false and misleading extrajudicial statements about Patton Boggs…in the media, [and] vexatious threats to seek to disqualify Patton Boggs based on meritless allegations of conflicts.”

The actions, Patton contends, “were taken with the intent to intimidate Patton Boggs into withdrawing from representing its clients, to induce a breach of contract between Patton Boggs and its clients, and to warn off any other law firm that might dare to oppose Chevron,” wrote Washington partner and general counsel Charles Talisman on behalf of Newark, N.J.-based partners James Tyrrell Jr., Anthony Laura and Eric Westenberger.

Patton filed suit against Chevron in U.S. District Court for the District of Columbia in November 2010, seeking a declaration that its work on behalf of Ecuadorian plaintiffs did not run afoul of professional conduct standards. In April, U.S. District Judge Henry Kennedy Jr. declined to hear the claims over whether Patton could continue to represent the plaintiffs’ interests in actions against the oil giant. Four months later, Kennedy again dismissed a similar complaint, amended to reflect the additional claims rejected in the reconsideration motion.

“By neglecting to raise these arguments earlier, [Patton Boggs] simply failed to take proper advantage of that opportunity,” Kennedy wrote in his Aug. 8 opinion. “That lapse does not entitle Patton Boggs to a second bite at the apple.”

AMAZON ALLEGATIONS

Chevron has faced almost two decades of litigation over alleged pollution by Texaco, a company it purchased in 2001. The initial allegations involved claims that for several years until 1993, the company dumped more than 18 billion gallons of polluted water into forests and rivers in the Amazon, making local resident populations sick.

In February 2011, Chevron was ordered by Ecuadoran courts to pay $18 billion in damages. Both Chevron and the plaintiffs, a group of Ecuadorians, appealed. In September, a federal appeals court in New York reversed an order that froze enforcement of the huge award.

In Patton’s Dec. 12 brief, Talisman accused Gibson and Chevron of engaging in a “campaign of instituting collateral proceedings in the American courts to portray itself as the victim, gain an unfair litigation advantage, and dry up the Ecuadorian Plaintiffs’ limited resources.”

Gibson filed its response on Dec. 14, accusing the firm of using the motion to launch “unfounded attacks” on Gibson and Chevron. The response goes on to outline alleged “fraudulent practices — detailed in the orders of more than a dozen federal courts — engaged in by Patton Boggs and its co-counsel in procuring a corrupt, $18.2 billion dollar judgment for use in their attempts to extort a ‘settlement’ from Chevron.”

Gibson contends that internal e-mails sent among Patton attorneys outline their strategy for “cleansing” a supposed neutral report on the alleged contamination.

Last December, Gibson attorneys accused Patton of “secretly working behind the scenes” in support of the Ecuadorian plaintiffs, according to media reports. A Gibson partner argued that Patton shouldn’t be able to represent the plaintiffs because of a conflict of interest. In July 2010, Patton acquired the Breaux-Lott Leadership Group, which had lobbied for Chevron in the matter. Gibson is arguing that the relationship should disqualify Patton from being able to represent the Ecuadorians.

Aside from strongly worded court filings, both sides have been engaged in extensive public relations campaigns. Web sites like ChevronToxico bombard visitors with images of oil-soaked rainforests and sympathetic-looking Ecuadorians. Chevron’s Web site has an entire subsection dedicated to their claims of fraud on the part of the plaintiffs featuring outtakes from the documentary Crude, which depicts former co-counsel for the plaintiffs, Steven Donziger, talking about the alleged intimidation of local judges.

In interviews, neither sided backed down. Gibson partner Theodore Boutrous Jr. said that Patton’s claims had been rejected several times before by Kennedy.

“This is a frivolous appeal of a frivolous lawsuit that Judge Kennedy ­rejected three times,” Boutrous said. He said the evidence of fraud comes from ­internal e-mails and video recordings of the plaintiffs’ attorneys openly talking about intimidation and fraud. “On the science, the plaintiffs had to cook the books and cook up evidence and they were exposed,” Boutrous said. “That is what the record reflects and we are defending our clients against what we believe is a massive fraud.”

Boutrous said he is confident that if given the opportunity for more discovery, more improprieties in the case would be revealed. “If we would obtain more discovery from Patton Boggs, there would be a strong chance that it would add to the mountain of evidence that this case is a fraud.”

Patton’s Tyrrell countered that Ken­nedy erred when dismissing the claims. “Patton Boggs alleged that the defendants’ improper conduct resulted in an undue burden performing under the contract,” Tyrrell said. “While Chevron was quick to say Patton Boggs had a conflict of interest, it argued that the district court should not decide that question.” Tyrrell took aim at what he called Chevron’s “high priced PR machine,” which so far, he said, has proven effective. “We stood up for the poor people of Ecuador and as a result, our name and reputation has been dragged through the mud,” he said. Oral arguments in the appeal are scheduled for March.

Michael Downey, a legal ethics expert and partner at Armstrong Teasdale in St. Louis, said this type of back and forth can end up harming the firm’s business in the long run. “It’s fun to watch, but it’s not fun to be a part of and it can hurt the underlying litigation,” he said. “Fights between law firms tend to become very public and lawyers engage in one-upmanship.”

Downey said this type of “bare-knuckle litigation” could make it more difficult should the two sides try to reach a settlement agreement. “This type of campaign often makes the fight more personal,” Downey said. “For some lawyers it makes it more difficult to negotiate.”

Matthew Huisman can be reached at ­mhuisman@alm.com.