RALEIGH, N.C. (AP) — In an unusually public fight, a Cherokee advocacy group is challenging a half-million dollars in extra pay the Tribal Council recently approved for itself, saying the North Carolina tribe can't afford raises for top officials while other services suffer.

The dispute has exposed details of tribal operations not often seen by outsiders and comes months before elections for top tribal posts.

The group argues that Eastern Band of Cherokee Indians lawmakers violated tribal law when they voted in October to give current and former council members raises retroactive to 2010, according to a letter to the council. The raises and back pay through 2015 exceed $500,000, and hundreds of thousands more in tribal funds will go to adjusted retirement benefits, the group says.

"At a time when vital Tribal programs in the areas of health, elder services, families and children continue to be underfunded, such exploitation of public office for personal gain is simply unconscionable," the letter dated April 16 states.

The group's Asheville-based attorney, Meghann Burke, said the Eastern Band of Cherokee Indians for Justice and Accountability plans to file a lawsuit in Cherokee Tribal Court if the council doesn't return the money by its May 7 meeting.

The group quotes tribal law as saying pay raises can't go into effect until the council's next term and that increases "shall not exceed the amount appropriated in that fiscal year for tribal employees."

All 12 Tribal Council members, who serve two-year terms, as well as the principal chief, who serves a four-year term, are up for election in the fall.

Tribal lawmakers passed the pay raises 9-1, with two sitting out, in their budget in October.

Budget documents obtained by the advocacy group show each member received a raise of about $10,000 for the fiscal year starting in October. The new salaries range from about $80,000 for most members to about $86,000 for chairwoman Terri Henry.

The group says several former council members also received retroactive payments of as much as nearly $24,000.

The members who sat out of the vote, Teresa McCoy and Albert Rose, filed protests and unsuccessfully sought to undo the raises.

A memo from Rose to Henry says the "Tribal Council cannot institute a pay increase until the next Council is seated" and the raises are "a direct violation" of tribal law.

If filed, the advocacy group's lawsuit would ask the court to declare the raises invalid and make the council members return the money.

The tribe's acting attorney general, Hannah Smith, and Tribal Council Vice Chairman Bill Taylor declined to comment, and Henry didn't respond to a phone message. Principal Chief Michell Hicks didn't return a message left Wednesday with his assistant.

In the past, dismay over raises for the council led to changes in the law. The 2004 resolution that became the law on council pay raises said tribe members felt the panel had previously given itself unfair raises of $10,000 or more.

"Tribal Council should set the example for curbing spending," says the unanimously passed resolution.

Documents obtained by the advocacy group show average annual pay increases for tribal employees were between 2 and 4 percent annually for the decade ending in 2013. A 2014 memo from Smith to top tribal officials says tribal employees are in a separate category from members of the government.

The tribe has approximately 15,000 enrolled members and employs about 4,000 in government and tribal businesses, spokeswoman Lynne Harlan said.

Most of the tribal government's revenue comes from gambling operations anchored by the sprawling Harrah's Cherokee Hotel and Casino, and the tribe is building a second casino. A report by an outside accounting firm showed that gambling provided nine-tenths of tribal government revenues for the 2008 and 2009 fiscal years.

The dispute provides a wider look at tribal operations than outsiders typically get. The tribe's laws guarantee enrolled members — but not necessarily others — access to public records and meetings.

A reporter for the Smoky Mountain News, a weekly newspaper that has frequently covered the tribe, wrote in December that she and other journalists were denied entry to a meeting that month.

Becky Walker, one of the leaders of Eastern Band of Cherokee Indians for Justice and Accountability, said a core group of 6 to 10 members has participated for years but support has swelled since the decision on pay raises.

"We have been attending meetings for years ... and have been really upset with some of the decisions," she said, adding that this is the first time they've hired a lawyer to take action.

There were public protests of the decision, and Walker says she's heard from many tribe employees who are upset but afraid to speak out.

Concerns include that the tribe has overextended itself with the new casino and other businesses.

"A lot of the enrolled members have concerns about how much debt we're in," she said.