MIDDLETON, Wis. (AP) -

Gov. Scott Walker says he doesn't have a number in mind for how much he wants to grow the private-school voucher program, should he be elected to a second term.

Walker said Wednesday after touring a sensor manufacturer in Middleton that he wants to grow the program in stages, so there is capacity for all the students who wish to participate.

The program allows for students in participating public school districts to use a taxpayer subsidy to attend a private school. Walker is a strong advocate for growing the program, which currently has a statewide enrollment cap of 1,000 students outside of Milwaukee and Racine.

Walker's opponent for re-election Democrat Mary Burke opposes the statewide voucher program and has said she wants to reduce the number of vouchers overall.