Prince William County’s landmark proposal to crack down on illegal immigration crashed into an unexpected roadblock Tuesday, when projections of an enormous multimillion-dollar budget shortfall caused the board to delay funding the effort. The resolution — which would have given officers the authority to check the status of suspected illegal immigrants arrested for any crime, including traffic violations — will be debated again on Oct. 16 after a retreat where the supervisors will be given details on next year’s financial picture.

“The citizens need to know there is a shortage in the revenue stream and there is some cost to this,” Supervisor Maureen Caddigan said.