Cook County commissioners on Wednesday could take center stage in the nation’s immigration debate if they enact a proposal that would begin freeing some jail inmates wanted by federal authorities.

The measure requires the sheriff to decline Immigration and Customs Enforcement requests known as detainers “unless there is a written agreement with the federal government by which all costs incurred” by the county are reimbursed.

County Board Commissioner Jesús García, D-Chicago, introduced a similar proposal in July but quickly withdrew it, saying it needed rethinking. García has refined the measure and picked up nine other sponsors, including Board President Toni Preckwinkle.

The inmates remain in the county’s massive jail up to 48 hours beyond what their criminal cases require. ICE detainers enabled the federal agency to take custody of 1,665 of the jail’s inmates in 2010, according to Sheriff Tom Dart.

Dart’s office says complying with the detainers last year cost roughly $250,000.

An ICE statement calls the detainers “critical” for deporting “criminal aliens and others who have no legal right to remain in the United States.”

But García says the holds enable ICE to sweep up too many immigrants who pose little or no risk to public safety. “These people have been cleared of charges or have posted bond,” he says.

García says the detainers also cost taxpayers too much and spread fear of local police — claims disputed by pro-enforcement groups such as the Federation for American Immigration Reform.

ICE didn’t immediately comment on the revamped proposal but sent a statement warning that “jurisdictions that ignore detainers bear the risk of possible public safety risks.”

The federal government does not reimburse any local jurisdiction in the country for costs associated with the immigration detainers, according to ICE spokeswoman Gail Montenegro.

Commissioners could approve the proposal at their meeting Wednesday morning. It would take effect “immediately upon adoption,” the measure says.

“As far as I know, Cook County would be the first local jurisdiction in the country to quit complying with ICE detainer requests,” says Chris Newman, legal director of the Los Angeles-based National Day Laborer Organizing Network, a group that leads opposition to the holds.

The proposal comes as a class-action suit in federal court challenges use of the detainers. Filed by the Chicago-based National Immigrant Justice Center, the suit charges that asking local police to detain immigrants when there is no evidence of illegal activity is unconstitutional.

Correction: An earlier version of this story misstated what Sheriff Tom Dart’s office estimates that its ICE detainer compliance costs the county. A sheriff’s spokesman says the cost last year was roughly $250,000.