WASHINGTON — A freshman Democratic senator accused Barack Obama Tuesday of failing to provide presidential leadership on a worsening national deficit as the Democratic Senate leader charged that Republicans are trying to block an up-or-down vote on a GOP bill containing substantial budget cuts.

Joe Manchin, D-W.Va., called on Obama to lead "tough negotiations" on wrapping up last year's unfinished budget work and said that "right now, that is not happening."

"When it comes to an issue of significant national importance, the president must lead," Manchin said.

Immediately thereafter, Senate Majority Leader Harry Reid charged that Senate Republicans are running away from a divisive House GOP plan that would cut domestic agencies by 13 percent, on average. He said Republicans instead want procedural votes that would give them political cover from the House GOP measure's harsh elements, such as cuts to Head Start for preschoolers from poor families and Pell Grants for low-income college students.

"Republicans know that once the country sees what's in the fine print, it will run away from it as fast as they can," said Reid, D-Nev. "Now it seems Republicans themselves must have finally read their own budget. Because now even they're running away from it."

The idea behind promised votes on the House GOP plan and a milder alternative from Senate Democrats is to prod the Obama administration, Republicans dominating the House and the Democratic-led Senate to settle gaping differences. The goal is a measure setting agency operating budgets through the rest of the fiscal year, which ends Sept. 30.

Looming in the background is the issue of keeping the government running after a short-term funding measure expires in less than two weeks. Another bill would be necessary to prevent a government shutdown, which neither side claims is desirable.

Democrats say the votes in the Senate would demonstrate to tea party-backed House GOP freshmen that their bill is a dead issue in the Senate and that they need to move closer to their demands for smaller budget cuts.

Neither measure can muster the 60 votes required under Senate procedures to advance; not a single Democrat is likely to vote for the GOP measure, and some may shy away from the Democratic bill as well. That could put pressure on House Speaker John Boehner, R-Ohio, as well as other congressional leaders of both parties to find a compromise.

"I'm sure that Speaker Boehner will be sitting down with his caucus and say: 'Well, what's our next position? Where do we go from here?' " said Sen. Dick Durbin, D-Ill., the No. 2 man in the Senate's Democratic leadership.

By the same standard, the vote on the Senate Democratic alternative — it would cut about $5 billion from domestic agencies compared with about $60 billion under the House GOP plan — is unlikely to get unanimous support from Democrats, especially moderates — like Manchin — up for re-election in 2012.

One such Democrat, Claire McCaskill of Missouri, said the Democratic measure "doesn't go far enough" but she hadn't decided whether to support it. Manchin agreed and said the kubuki theater was a foolish waste of time.

"Republicans will say Democrats don't go far enough. Democrats will say Republicans go too far," Manchin said. "The truth is both are right, and both proposals will fail. Worse still, everyone in Congress knows they will fail."

Meanwhile, Senate Minority Leader Mitch McConnell, R-Ky., said the ongoing debate over funding federal agencies through Sept. 30 "is just a dress rehearsal" for a bigger debate on benefit programs like Medicare that are the real drivers of the spiraling federal budget. He said the Senate Democratic plan, which ponies up $5 billion in further spending cuts — compared to about $60 billion in cuts passed by the House — falls woefully short.

"Democrats are going to have to do a lot better than this if we stand a chance of getting our nation's fiscal house in order," McConnell said. "Frankly, it's embarrassing.

The House GOP measure makes sweeping cuts to domestic programs whose budgets are set each year by Congress, including politically sensitive programs beyond Head Start and Pell Grants. Money for food inspection, enforcing environmental regulations, grants to local schools and police and fire departments, and community development grants for local governments would also be sharply reduced.

The Democratic alternative would cut spending by $11 billion from last year's levels and limit increases for the Pentagon's core military operations to just 1 percent, far less than increases received in previous years.

The Senate Democratic plan falls well shy of the cuts sought by Republicans but demonstrates considerable movement from where the party was last year when it sought to pass an omnibus spending bill with a price tag $30 billion higher than the current measure. Senate Republicans blocked the effort.