MADISON, Wis. — Gov. Scott Walker's state budget proposal is coming into clearer focus, with the second term Republican revealing major portions including $300 million in cuts to the University of Wisconsin System and no new taxes to pay for transportation projects.

But much also remains unknown Monday, the day before Walker is to release his two-year spending plan to the Legislature.

Walker faces a roughly $2 billion shortfall by mid-2017, based on spending requests submitted by state agencies.

He has released portions of his budget in recent days, but he hasn't said whether public schools will see an increase in aid, whether he will expand the private school voucher program and pay for it, or whether he will cut property taxes as promised.

Walker will deliver the budget Tuesday night.