After suing federal officials and winning billions of dollars, American Indian tribal leaders are seeking the government’s help against lawyers on their own side.

The National Congress of American Indians adopted a resolution last week backing a bill to cap attorney compensation at $50 million in a $3.4 billion settlement over land and trust asset mismanagement by the federal government.

The legislation could change the terms of a settlement between the federal government and American Indians over a dispute that began 15 years ago. Elouise Cobell, a member of the Blackfeet Tribe in Montana, led a group of American Indians in filing suit in 1996 against the departments of Interior and Treasury after she noticed discrepancies in the way officials had recorded assets and land belonging to the tribes.

The class action lawsuit grew to include 500,000 plaintiffs before the government agreed to pay a $3.4 billion settlement in 2009. President Barack Obama signed a bill into law in December to approve that amount, including $50 million to $99.9 million in attorney’s fees. The plaintiffs’ lawyers then petitioned for $223 million in compensation, saying an agreement with the plaintiffs had entitled them to that much.

Two prominent Republicans on the Natural Resources Committee took up the cause against the lawyers on behalf of tribal leaders. Chairman Doc Hastings (Wash.) and Rep. Don Young (Alaska) filed a bill to cap the lawyers’ take at $50 million. The Affiliated Tribes of Northwest Indians have passed a resolution supporting the bill.

The lawyers have since said they will accept $99.9 million, the limit from the original settlement. But the lawmakers and tribes continue to push for $50 million, saying the rest of the money should go to the individual plaintiffs.

“My number one concern has always been the fair treatment of the 500,000 individuals in Indian Country and ensuring that they — not trial lawyers — receive the money they deserve,” Hastings said in a statement.

Last month, Hastings also subpoenaed two lawyers on the case, Keith Harper and Dennis Gingold, requesting information about their fee arrangements and billing. A spokesman for Hastings said the lawmaker did so only after the attorneys refused to hand over the information.

“It’s probably hard to find a bigger proponent of Native rights in Congress than Don Young. He and Chairman Hastings are doing this so that the settlement class gets what they were promised and their money isn’t going towards these absurd lawyer fees,” Hastings spokesman Spencer Pederson said.

But Democrats questioned Hastings’ intentions. In a strongly worded letter against the subpoenas, Natural Resources ranking member Ed Markey said Congressional interference in the judicial matter could undermine the settlement, which has not been finalized, and could force the tribes to return to court.

“Under previous Republican Chairman, this Committee injected itself into court proceedings. … The end result of these intrusions was, at best, to create the appearance of political gamesmanship in the judicial process and, at worst, to actually tip the scales of justice,” the Massachusetts Democrat wrote in a letter to Hastings. “The secret and unilateral nature of these subpoenas raises the specter of a return to these unfortunate practices.”

Eben Burnham-Snyder, a spokesman for Markey, said the attempt to limit attorney’s fees in the Cobell case was just one example of that.

Republicans have also introduced legislation to give farmers in California’s San Joaquin River Delta more access to water, potentially undermining restoration efforts there under a 2006 settlement.

“This is now sort of a continuation of a pattern in the Natural Resources Committee where, if a legal settlement has been reached, the Republicans on the committee overreach and try to upend the previously existing agreement,” Burnham-Snyder said.

The Cobell case lawyers also alleged the Republicans have ulterior motives.

“Hastings is no friend of Indian Country, and he’s been trying to kill the settlement since we announced it in 2009,” Geoffrey Rempel, an accountant with the litigation team, said in an interview.

Pederson called such allegations “ridiculous” and said the bill, which is still in committee, would not kill the settlement.

“It’s appropriate for Congress to intervene because the reason this settlement exists is because Congress passed it,” Pederson said in an interview.

Rempel said the lawyers have backed down from their initial request for $223 million ­— about 15 percent of the $1.5 billion to be dispersed to members of the class action lawsuit — in the hopes of resolving the matter.

Of the remaining settlement money, $1.9 billion is expected to fund an Interior Department program to purchase land benefiting tribal communities, and $60 million will fund scholarships for American Indian youth.

Even though tribal leaders argue the attorney compensation unfairly cuts into their share, Rempel said individual plaintiffs are on his side.

“We represent individuals that have been largely disenfranchised by tribal organizations over the past 100 years,” Rempel said. “My clients have no love of tribes and frequently find themselves on the other sides of the tribes.”

Last week’s resolution by tribal leaders called into question the numbers of hours the lawyers billed, whether fees had been inflated and “extravagant dining and hotel expenses.”

A fairness hearing began Monday to determine, among other matters, how much the lawyers should get paid.