Prince William County supervisors have voted to spend nearly all of the county's contingency reserve fund to pay for a crackdown on illegal immigration.

The board of supervisors voted unanimously to spend $800,000 from the cash-strapped county's reserve fund to pay for the efforts. That leaves less than $3,400 in the fund for the rest of the fiscal year, which ends in June.

The county has already given $325,000 to the police department for the initiative.

The new policies require police to check the immigration status of anyone who is detained if the officer has probable cause to believe the person is an illegal immigrant. It also makes illegal immigrants ineligible for certain county services, such as housing assistance and business licenses.

Opponents say the county will be forced to cut services in next year's budget to make up for the cost of the crackdown and tax revenue that is lost when immigrants leave the area.