MADISON, Wis. (AP) -- Wisconsin lawmakers have passed a bill that would limit further expansion of Wisconsin's school voucher program.

The state Assembly approved the measure on a voice vote Tuesday. It cleared the Senate in October and now heads to Gov. Scott Walker.

The voucher program provides parents in eligible school districts with state subsidies to defray their children's private school tuition. Conservatives insist it gives children in underperforming schools an alternative. But opponents say it takes needed money away from public schools and is part of a broader agenda to defund public education.

Walker has consistently backed the bill, even though he also supports expanding the voucher program that began in and had been limited to Milwaukee.