MADISON, WI (WTAQ) - Democrats tried but failed Thursday to force the state Assembly to vote on restricting the expansion of Wisconsin’s private school voucher program.

The tax-funded vouchers are given to low-income kids in Milwaukee County and Racine, so they can attend private schools.

Concerns were raised last summer, after lawmakers approved a last-minute budget amendment that critics said could expand the voucher program statewide.

Program supporters said that was not the intent – and they promised to pass a new bill that requires legislative approval before the voucher program can be expanded to places like Green Bay.

The Senate passed the bill last fall, and Governor Scott Walker said he would sign it.

But the measure’s locked up in the Assembly – and Oshkosh Democrat Gordon Hintz said he wanted to make sure Republicans don’t renege on their deal.

The bill would die if it’s not passed in a month, when the Legislature is due to adjourn for the year.

The Assembly voted 58-37 Thursday, with all Democrats voting no, to keep the bill locked up in a committee for now.

Racine County Republican Robin Vos says he’s still trying to round up enough votes to pass the measure – and he expects that to happen before the session ends.