WASHINGTON – Congressional Republicans, under fire for increasing federal spending and a $300 billion deficit, are attempting to burnish their election-year image by pushing the largest overhaul of the budget process in more than a decade.

The House last week voted to give President Bush a type of line-item veto that would allow him to target the funding lawmakers reserve for their pet projects.The Senate is contemplating a more ambitious plan that might force lawmakers to make big cuts in entitlement spending in coming years to balance the government’s books.

The proposals either aren’t likely to be enacted or wouldn’t have much effect if they were, budget experts said. Still, they allow Republicans to portray themselves as tough on spending as they defend their congressional majorities in the November election.

“These budget-process reform ideas tend to be fig leaves,” said Phil Joyce, a former Congressional Budget Office analyst who now teaches at George Washington University in Washington. “The things they could do that would actually have the effect of putting the budget on a better footing are all things that would inflict pain on some people.”

Discretionary spending – the portion of the budget subject to annual review by Congress – was higher last year than at any time since 1993, according to the CBO. The nonpartisan agency estimated such spending last year equaled 7.9% of gross domestic product, up from 6.5% in 2001, when Mr. Bush took office.

Those spending increases haven’t gone unnoticed by Republican voters, said Whit Ayres, an Alexandria, Virginia-based Republican pollster. “The total amount of spending, and the growth in spending, sticks in the craw of core Republican voters,” Mr. Ayres said.

Many Republicans said the proposal for a line-item veto – allowing the president to target specific provisions in broad spending bills – would give Mr. Bush more power to root out funding for lawmakers’ special projects, called earmarks.

Still, even some of the measure’s supporters aren’t certain it will have much effect, partly because earmarks comprise such a small share of federal spending – about 2% last year, according to the Congressional Research Service. Some lawmakers also said Congress, which under Mr. Bush’s proposal would have to ratify any cuts, would be unlikely to do so.

“We’ve become addicted to earmarks,” said Rep. Jeff Flake, an Arizona Republican whose attempts to kill such projects have been repeatedly rejected by his colleagues. “This kind of addiction is tough to break.”

Donald Marron, the acting CBO director, told the Senate Budget Committee last month that the plan may end up increasing federal spending. He said lawmakers may strike deals to support the president’s spending priorities in return for his agreement not to use the line-item authority, as has happened in many states that allow line-item vetoes.

The House vote nevertheless enabled Republicans to go on the offensive against Democrats who opposed the plan. The Republican National Committee e-mailed reporters the day after the vote, accusing Rep. Julia Carson, a Democrat of Indiana, of casting a “reckless vote against spending restraint” that shows “she has lost sight of what is important to her constituents.”

The broader Senate Republican plan, which also includes the line-item provision, would cap the size of the deficit in an attempt to balance by the budget by 2012, create a commission charged with finding programs to kill and put Congress on a two- year budget cycle so lawmakers could spend more time examining how well programs perform.

Such a plan might require lawmakers to cut Medicare and other entitlements by more than $200 billion in 2012, according to the Center on Budget and Policy Priorities, a Washington-based policy research group that opposes the proposal. Earlier this year, Congress rejected the Bush administration’s more modest proposal to cut entitlements by $65 billion over the next five years.

While the Senate budget overhaul is unlikely to pass this year, some Republicans said they are still eager to debate it to highlight the differences between the two parties’ fiscal policies.

“It presents a clear choice between those who want to balance the budget by raising taxes and those who want to balance the budget by cutting spending,” said Senator Cornyn, a Republican of Texas. “That will present a sharp contrast between different visions of governing.”

Democrats mocked the effort, saying Republicans, who control the White House and both chambers of Congress already have all the tools they need to cut federal spending.

“How can anybody take this seriously?” said Senator Conrad, the ranking Democrat on the Senate Budget Committee.” It’s the sound and the fury, signifying nothing.”