WASHINGTON – A Republican plan for the 2012 budget would cut more than $4 trillion over the next decade, more than even the president’s debt commission proposed, with spending caps as well as changes in the Medicare and Medicaid health programs, its principal author said Sunday.

The spending blueprint from Rep. Paul Ryan, the chairman of the House Budget Committee, is to be released Tuesday. It deals with the budget year that begins Oct. 1, not the current one that is the subject of negotiations aimed at preventing a partial government shutdown Friday.

Ryan told “Fox News Sunday” that budget writers are working out the 2012 numbers with the Congressional Budget Office, but he said the overall spending reductions would come to “a lot more” than $4 trillion. The debt commission named by President Obama recommended a plan that it said would achieve nearly $4 trillion in deficit reduction.

Ryan said Obama’s call for freezing nondefense discretionary spending actually locks in spending at high levels. Under the forthcoming GOP plan, spending would return to 2008 levels and thus cut $400 billion more over 10 years, Ryan said.

Speaking broadly about the proposal, Ryan said it would include:

• A “premium support system” for Medicare. In the future, older people would choose plans in the marketplace and the government would subsidize those plans. Ryan said that would differ from the voucher system he has proposed in the past. Those 55 and older would remain under the current Medicare system.

Ryan acknowledged that his proposal would shift more costs to Medicare recipients, especially what he called “wealthy seniors.” He did not define at what level someone would be considered wealthy.

• Block grants to states for Medicaid, the health program for the poor. Ryan disputed reports that the plan would seek savings of $1 trillion over 10 years from Medicaid, but would say only that the details would be in the plan.

“Medicare and Medicaid spending will go up every single year under our budget. They don’t just go up as much as they’re going right now,” he said. Ryan said governors have told members of Congress they want “the freedom to customize our Medicaid programs. … We want to get governors freedom to do that.”

• A statutory cap on actual discretionary spending as a percentage of the economy. While Ryan did not specify the amount during the interview, he said it would be at a lower level than proposed by Obama and would return the government to its “historic size.”

• Pro-growth tax changes, including lower tax rates and broadening the tax base. Ryan said overhauling taxes would boost the economy. The plan will not propose tax increases.

Ryan was a member of the bipartisan debt commission but voted against its final recommendations, saying they failed to cut spending on health care. The commission also endorsed tax increases along with painful spending cuts as necessary to dealing with the debt problem.

“We’re not going to go down the path of raising taxes on people and raising taxes on the economy. We want to go after the source of the problem, and that is spending,” Ryan said Sunday.

Ryan didn’t mention how the budget plan would address Social Security.

Democratic Sen. Mark Warner of Virginia was skeptical that Ryan’s proposal could achieve its targets without damaging social programs. He also questioned whether reductions in defense spending and seeking more revenue through tax reform would be part of the plan.

“I don’t know how you get there without taking basically a meat ax to those programs who protect the most vulnerable in the country,” Warner told CNN’s “State of the Union.”