Updated 11:45 a.m.

House Budget Committee Chairman Paul Ryan (R-Wis.) unveiled a spending proposal Tuesday that would slash more than $5 trillion in federal spending over the next decade, primarily by repealing President Obama's signature health law.

The 99-page plan is Ryan's last budget as head of the Budget Committee and amounts to a personal manifesto on government austerity from a man who has emerged as the GOP’s leading light on fiscal policy. Term-limited  as head of the budget panel, Ryan is vying to become chairman of the powerful tax-writing Ways and Means Committee next year, while still mulling a bid for president in 2016.

Ryan uses his final budget to distance himself from a tax overhaul advocated by the outgoing Ways and Means chairman, Rep. Dave Camp (R-Mich.), who on Monday announced plans to retire. The Ryan budget does not contain a counterproposal to Camp's, except to reassert the goal of a top individual tax rate of 25 percent, collapsing the current seven individual income-tax brackets into two brackets and calling for consideration of several ideas to overhaul the tax system.

Ryan also proposes no increase in defense spending, instead adhering to the discretionary spending caps he negotiated with Senate Budget Committee Chairman Patty Murray (D-Wash.) in December.

The House Budget Committee is expected to debate and pass the spending plan Wednesday, and GOP leaders have said they will hold a vote on Ryan's proposal. It is uncertain whether the proposal will be acceptable to a majority of House Republicans, a group often sharply divided on spending matters, and to the broader GOP establishment, which is carefully tracking policy proposals from potential presidential candidates.

The White House rejected Ryan's plan and said in a statement that it "would slow the economy, stack the deck against the middle class and threaten the guaranteed benefits seniors have paid for and earned."

Senate Majority Leader Harry M. Reid (D-Nev.) slammed the proposal as "Kochtopia," or fulfilling the requests of conservative businessmen Charles and David  Koch, who are financing tens of millions of dollars in advertisements this year to discredit Democratic congressional candidates. And House Minority Whip Steny Hoyer (D-Md.) told reporters that the proposal is "an unserious partisan budget" and "as unrealistic as previous budgets — and some would argue even more so."

But any fighting between Democrats and Republicans on spending will not result in the deadline-driven battles of recent years. That's because the House and Senate agreed this year to a spending plan that runs through the end of fiscal 2015. While the GOP-controlled House is expected to debate and pass Ryan's plan, it will serve only as a political show vote since Democrats controlling the Senate do not plan to propose or vote on a budget plan.

Ryan's plan recycles several proposals from previous years that remain popular with GOP lawmakers, including repealing the benefits of the Affordable Care Act. But he keeps the taxes and cuts to Medicare mandated by the law. He calls for privatizing Medicare by changing it from an entitlement program into a voucher-style program. Democrats have previously opposed this proposal and used it as the centerpiece of their arguments against Ryan’s spending proposals. He also proposes cuts to other domestic agencies, reductions in the size of the federal workforce and cuts in retirement benefits for federal workers. And he once again fails to provide a plan to overhaul Social Security.

Ryan released a stinging critique of the government's anti-poverty policies last month and billed it as a prelude to his budget plan. But the proposal lacks a full welfare reform plan and provides few ideas on overhauling the nation’s social programs, instead advocating smaller steps that would "encourage work" and seek to boost economic growth.

Ryan does propose turning the federal food stamp program, formally known as the Supplemental Nutrition Assistance Program (SNAP), into a block grant program "tailored for each state’s low-income population." Reforms would include stiffer work requirements and new education and job training requirements. The proposal builds on changes pushed by Republicans in the most recent farm bill, which authorizes SNAP funding. None of Ryan's proposed changes to the program would begin until the next farm bill is authorized in 2019 and would save nearly $125 billion over a decade.

Overall, Ryan would cut about $5.1 trillion from projected spending over the next decade, with nearly $3 trillion coming from repealing the health-care law and revamping Medicaid. Still, Ryan's proposals fall short of balancing the budget, forcing him to resort to a vague promise of new revenue from "economic growth" to meet his goal of wiping out deficits by 2024.

The new budget plan is dramatically different in structure from any of Ryan's previous proposals, which were mostly sweeping vision statements. The proposal unveiled Tuesday plods function-by-function through the dozens of appropriations categories, with the aim apparently of recommending savings in each category. That bodes well for plans to conduct a full appropriations process in the House and Senate this year, but it results in more modest proposals than in years past.

Lori A. Montgomery contributed to this report.