Virginia Gov. Bob McDonnell on Monday proposed adding a net $211 million in new spending to the state's budget even as the state is coping with economic uncertainty created by looming federal tax increases and spending cuts.

The governor sent to the General Assembly a series of budget amendments that would cut more than $500 million in spending from the state's $80 billion, two-year budget. But McDonnell also proposed adding $736 million in new spending, including raises for Virginia's teachers and more money for state colleges.

"The budget amendments that I am presenting today ... recognize the realities of this economy and the looming uncertainty of budget gridlock in Washington and the fiscal cliff are having on our economy," McDonnell said.

McDonnell is again proposing to shift a portion of the state sales tax away from the general fund budget to provide $48 million to pay for roads. Lawmakers rejected a similar proposal from the governor earlier this year, saying the plan shifted money away from schools, social programs and other priorities.

Missing from the governor's budget amendments, however, was a plan that McDonnell promised would add $500 million a year for roads by 2018. The governor still hasn't said how he'll raise that money.

Democrats immediately rejected the Republican governor's plan to use sales tax revenue for roads, saying the money's needed for other critical services.

"We will fight hard not to switch any current source of general fund revenue into transportation because we've already cut as much as we can cut from higher education and K-12 education," said Del. Mark Sickles, D-Franconia. "The amount he could divert is so small. It's really just a fig leaf trying to cover an enormous backlog in maintenance and a construction shortfall."

McDonnell's amendments would provide an extra $50 million for the state's rainy day fund, $64 million for state employee health insurance, $14 million to build prisons and reduce overcrowding, $30 million for state universities and $45 million in restored aid for localities.

McDonnell also included $59 million for a 2 percent pay increase for teachers that he announced last week, though teachers will get the money only if McDonnell is successful in changing personnel rules so it's easier to fire ineffective teachers.

Fairfax County Board of Supervisors Chairwoman Sharon Bulova said the county is glad to see aid to local governments restored. But that's being offset by the $12 million McDonnell proposes cutting from a salary assistance program that helps Fairfax and other Northern Virginia jurisdictions recruit teachers who otherwise couldn't afford to live in the affluent region.

"The less money we get from the state, the more of a hole it puts in the school budget," Bulova said. "And that makes it a challenge for us because revenues are pretty flat right now."