Arizona taxpayers pay an estimated .3 billion a year for health care, education and prison costs of illegal immigrants, according to a report released Thursday by a national group backing Protect Arizona Now.

The Federation for American Immigration Reform charges in its report that Arizona spends 0 million annually to educate illegal immigrants and their children, 0 million for health care and million on prison costs of undocumented immigrants.

Dan Stein, FAIR's executive director, said Thursday in Phoenix that the report used U.S. census data, state agencies' reports and other published materials. But he couldn't specify exactly how the agency reached the conclusions.

Jeff Passel, an immigration expert with the Washington-based Urban Institute, also criticized FAIR's report, saying the authors highlighted selective costs without taking into account the full scope of benefits U.S. employers and consumers get from immigrant labor.

"To some degree, these kinds of studies about the net cost of immigrants are always done with a political agenda in mind," he said.

But Stein defended his group report, saying, "These are accurate numbers."

Backers of Protect Arizona Now hope the report will fuel the immigration debate in Arizona and help them collect 122,600 signatures by July 1 to put the measure on the November ballot. Organizers said they have collected more than 60,000 signatures, but top leaders are embroiled in an internal fight that could put the brakes on the effort.

This week Kathy McKee, the state director for Protect Arizona Now, replaced Rusty Childress as the group's treasurer, a move he and others dispute. McKee said Thursday that she is considering legal action to stop Childress and others from working on behalf of Protect Arizona Now.

Still, state Reps. Randy Graf, R-Green Valley, and Russell Pearce, R-Mesa, advisers of Protect Arizona Now, said things will be worked out with McKee.

"Nothing has changed," Pearce said. "This is bigger than Kathy and nobody has lost any enthusiasm of putting this on the ballot."

Similar measures in California and Colorado have failed to be placed on this year's ballot so organizers say they are focusing more effort on Arizona.

"The (U.S.-Mexican) border shouldn't be an open gate," said Dawn Lee, a 41-year-old Phoenix woman who attended Thursday's rally to hear about FAIR's report. She signed the petition to put Protect Arizona Now on the ballot.

Jack Martin, who authored FAIR's report, indirectly criticized Arizona lawmakers who have proposed a bill in Congress that would give millions of undocumented immigrants legal status as long as they can prove they have a job and pass criminal background checks. Those who qualify for the temporary visas could become eligible for permanent legal status.

The Arizona Republicans championing the federal measure are Sen. John McCain, Rep. Jim Kolbe of Tucson and Rep. Jeff Flake of Mesa. They have argued their plan would not grant any immigrant amnesty, but would create a legal way for scores of U.S. businesses to fill jobs unwanted by most Americans.

"There's no doubt that Arizona bears the brunt of our country's failed illegal immigration policy," Flake said. "And for that reason, I think that most Arizonans recognize that a comprehensive temporary worker program would alleviate many of the problems we now face."