WASHINGTON — When the bill to give federal recognition to Native Hawaiians comes up for Senate debate next week, Sen. Jon Kyl will be armed with amendments to modify it.

Kyl, R-Ariz., the bill's leading opponent, said that one of his proposals would stop the process for federal recognition unless it's approved in a referendum of all Hawai'i residents.

"I think that makes eminent sense," said Kyl, chairman of the Republican Policy Committee. "I think that is an amendment that will pass."

But Sen. Daniel K. Akaka, D-Hawai'i, said the process outlined in the bill already allows for a referendum. "Before any of the negotiations can be implemented, state and federal laws have to be amended and, most likely, the state constitution will have to be amended," said Akaka, chief sponsor of the bill that takes his name.

The disagreement between Akaka and Kyl provide a snapshot of the arguments that are likely to be made on the Senate floor when debate opens next week on the proposal that has been around for five years.

Akaka said if the state Department of Hawaiian Home Lands and the Office of Hawaiian Affairs become a part of the Native Hawaiian governing entity that would be created, then Hawai'i's state constitution would need to be modified.

That would allow the state to hold a referendum of all residents to approve any needed changes to the state constitution, Akaka said. The Hawai'i Legislature would have to approve any changes to state law, he added, and Congress would have to approve any changes to federal law.

Kyl declined to provide details on other amendments he intends to offer.

"What we have tried to do is identify what we think are some of the most vulnerable parts of the bill in terms of the way people would look at it and see whether they would like to make changes in those parts of the bill," Kyl said.

Sen. Dan Inouye, D-Hawai'i, declined to comment on Kyl's referendum amendment, saying it would be premature because he has not yet seen the proposal, according to spokesman Mike Yuen.

"With Senate floor debate on this crucial legislation ... just a few days away, it is important to have a full reading of the precise language of any amendment that may be introduced," Yuen said. "Sen. Inouye reiterated that he is looking forward to the forthcoming floor debate."

Kyl issued a report last month saying the legislation would create a race-based government for Native Hawaiians and promote "racial division and ethnic separatism."

While he is leading Republican opposition to the bill, Kyl said he didn't know whether he had enough votes to block its passage. He also said he would not try to filibuster it.

"You understand that I'm keeping my commitment to try my best to ensure that we have an up-or-down vote and, therefore, 51 votes one way or the other wins," he said. "I don't have some of my colleagues talked into that yet, but I have a responsibility to try very hard and I believe that in the end, I will be successful in doing that to allow it to come to a straight up-or-down vote plus amendments."

The bill has the support of six Republicans, including Sen. John McCain of Arizona, chairman of the Indian Affairs Committee. With the Republicans and the backing of all 44 Democratic senators and the one independent — Sen. Jim Jeffords of Vermont — the bill would have at least a majority vote on the floor.

Despite the discussions about the bill over the past five years, some Republicans remain undecided about how they might vote.

"I need to talk and think and read more about it," said Sen. Craig Thomas, R-Wyo., a member of the Indian Affairs Committee, which approved the bill in the spring. "I'm a little concerned about it in that it seems like ... it's quite a different thing than sovereignty of the Indian tribes. I'm undecided on it because I'm uninformed."