RICHMOND -- Gov. Tim Kaine warned state lawmakers Monday that his administration will propose another round of budget cuts because of a slowing economy and said all state spending programs, including education, could be affected.

In a presentation to the General Assembly's money committees, Kaine said weaker-than-expected growth in key sources of tax revenue suggests the state will have a shortfall in its two-year, $77 billion budget. Kaine said his administration immediately will begin working on a new revenue forecast to determine the severity of the shortfall, then make decisions about budget cuts.

The governor said those decisions will be more difficult than spending cuts and other steps he and lawmakers have taken over the past year to offset revenue shortfalls.

"The task that lies before us is not an easy one," said Kaine, who already has imposed restrictions on discretionary spending and hiring. "The cuts we have made over the last year -- cuts based on solid data and careful prioritization -- have been tough. The next rounds will be more difficult."

Kaine said all programs, including public education, could face cuts. Kaine and lawmakers have exempted public schools from previous budget cuts.

"We will continue to do all we can to protect core services, but the need for tough decisions will require examination of all areas of state spending," he told lawmakers.

When asked about the possibility of education cuts after his speech, Kaine said: "We can't do anything that will be a big dislocation to operations that are currently under way, but everything does need to be on the table."

Republican legislators said they expect the shortfall to reach $1 billion and argued that Kaine should move more quickly to get a handle on the severity of the problem. They also accused Kaine of ignoring lawmakers' warnings earlier this year that his budget plan was based on overly optimistic revenue projections,

"He's got a job to do," said House Majority Leader Morgan Griffith, R-Salem. "He's the only person with a red pen. He needs to have an action plan."

Kaine discouraged "guesswork" about the severity of the deficit, preferring to wait for input from industry leaders, economic advisers and legislators who are part of a formal revenue forecasting process.

"Floating a number on the back of an envelope really doesn't make much sense," Kaine told reporters after his speech, noting that the budget cycle is less than 2 months old.

Kaine said weak growth in state sales and income tax collections in the second quarter are key factors behind the likely revenue shortage. But, he noted, other states are experiencing similar problems --including 20 states that failed to meet their revenue targets in the past fiscal year.

Kaine also warned that transportation revenue could be affected by downturns in gasoline tax and vehicle sales tax collections.

The bad budget news comes at a time when Kaine is being mentioned as a potential running mate for Democratic presidential candidate Barack Obama. Kaine refused to answer questions about Obama, who will be making campaign stops in Martinsville and Lynchburg on Wednesday. Griffith questioned whether the governor could manage the state's budget problems while pursuing a national office.

"With the serious issues facing Virginia, it would be difficult to do both," Griffith said.

Del. Lacey Putney, I-Bedford, the chairman of the House Appropriations Committee, said the administration should produce a revised revenue forecast within six weeks so that spending decisions can be made more quickly.

"We can ill afford to wait much longer without taking corrective action to align our spending with anticipated revenues," Putney said.

Legislators also pressed Secretary of Finance Richard Brown for some indication of the severity of the shortfall, but Brown said "it would probably be irresponsible of me" to make a projection before the forecasting process is completed.

"We need to take action sooner than later," said Sen. William Wampler, R-Bristol. "We don't see it getting any better."

Democrats defended Kaine's handling of the budget situation, saying the governor was being cautious but not alarmist.

"I think he's probably wise to hold off on the exact numbers," said Del. Onzlee Ware, D-Roanoke, a member of the House Appropriations Committee.

Sen. Edd Houck, D-Spotsylvania County, said the criticism of Kaine "is more politically motivated than anything."