Republican lawmakers moved ahead Monday on a doomed plan to amend the U.S. Constitution to require a balanced federal budget, one day after President Obama met with the top two House GOP leaders in hopes of reaching a debt-limit agreement that could win approval from the hostile House. 
 
 House Republicans insist that a constitutional mandate is the only way to impose discipline on Washington’s spending binges and spare the country future dangerous political showdowns like the one now speeding the country to the brink of its first-ever default. 
 
 Beyond requiring that the budget be balanced each year, the so-called “cut, cap and balance” measure under House consideration would require that the constitutional provision include annual spending caps and a supermajority to approve tax increases. 
 
 That plan faces almost certain defeat in the Senate, where many lawmakers moved ahead on Monday with a compromise proposal. 
 
 The current timeline, according to aides in both parties, would call for the Senate to unveil its bipartisan plan later this week and begin to consider it Saturday. With a week of parliamentary hurdles to clear, the Senate could pass its bill by July 29, leaving the House just four days to consider whether to approve the plan before Aug. 2, when the country would no longer be able to pay its bills. 
 
 Democrats are watching the action in the House warily. They hope that the cut, cap and balance measure will convince House Republicans that they need to sign on to the Senate compromise. 
 
 Obama issued a cautionary threat Monday to veto the measure should it pass Congress. The White House said the bill would set up an “unacceptable choice” between a disastrous failure to lift the nation’s borrowing limit or passing a balanced budget amendment that would require draconian spending cuts in Medicare, Social Security and other federal programs. 
 
 “This is a measure designed to . . . duck responsibility, dodge obligations and dismantle, eventually, if signed into law, our social safety net,” White House spokesman Jay Carney told reporters at his daily briefing. 
 
 Behind the public bluster were signs that quiet work continues on finding a compromise. 
 
 Obama met Sunday with House Speaker John A. Boehner (R-Ohio) and Republican Leader Eric Cantor (Va.) to discuss the way forward. While aides provided no details about the meeting, Treasury Secretary Timothy F. Geithner said in an interview Monday that he is “absolutely” confident a deal will be reached. 
 
 “Despite what you hear, and this is a complicated place, Washington, people are moving closer together,” he told CNBC. 
 
 In the Senate, Majority Leader Harry M. Reid (D-Nev.) and Republican Leader Mitch McConnell (Ky.) have been making quiet progress on a last-resort deal to allow the debt ceiling to be raised in return for about $1.5 trillion in spending cuts over 10 years. 
 
 A new idea also came from Oklahoma Republican Sen. Tom Coburn, who released a 600-page plan that he says would achieve $9 trillion in deficit savings over the next decade through a combination of proposals long anathema to both parties, including far-reaching spending cuts, entitlement reform and increased tax revenue. 
 
 Coburn challenged those in his party not to see the elimination of special-interest tax breaks as a tax increase, while maintaining that he does not support any effort to increase rates. 
 
 “Tax expenditures are not tax cuts,” he said. “Tax expenditures are socialism and corporate welfare. Tax expenditures are increases on anyone who does not receive the benefit or can’t hire a lobbyist or special interest group to manipulate the code to their favor.” 
 
 The House bill is an updated version of the kind of balanced budget amendment Republicans have coveted for years. 
 
 A dramatic shrink in the size of government would come in two steps. First, Congress would impose an immediate legal cap on spending that matches the budget written by Rep. Paul Ryan (R-Wis.), which covers the next 10 years. 
 
 Next, the debt ceiling would rise only after Congress approves sending a constitutional amendment to the states for ratification. That would require two-thirds of both chambers of Congress voting for it — an outcome that no one believes will happen. 
 
 While the measure does not specify how strict the spending cap should be, past proposals have included caps at 18 percent of gross domestic product, down from the current 24 percent. 
 
 White House economic adviser Jason Furman told reporters on a conference call that if defense were exempted from cuts, that kind of cap would require slashing 12 percent from the rest of the federal budget, including Social Security and Medicare, resulting in a $2,000 reduction in benefits for the average Social Security recipient. 
 
 Not even House passage of the measure is assured — some Republicans plan to oppose any legislation to lift the debt ceiling. House Republican Whip Kevin McCarthy (R-Calif.) on Monday predicted victory, but added that the leadership was “still working it.” 
 
 Leading conservative advocacy groups insist that Republicans must steer the measure through Congress before they would find a debt-ceiling increase acceptable. 
 
 The influential Club for Growth announced Monday that it supports the House measure — and that it would hold to account Republicans who support the Senate-brokered deal instead. 
 
 “A vote’s insufficient,” Tim Phillips, president of the tea party-affiliated Americans for Prosperity said recently. “It’s one thing to simply schedule a vote and say we gave you a vote. It’s another thing for it be elevated to a point where it’s part of the deal.” 
 
 More on PostPolitics.com 
 
 The Fix: Why Republicans don’t fear default 
 
 2Chambers: Nearly 30 percent of House skips votes as debt-limit deadline looms 
 
 Poll: Little confidence in leaders to deal with debt issue 
 
 Lori Montgomery, Felicia Sonmez and David Nakamura contributed to this report. ||||| The president has threatened to veto House Republicans' debt bill. | JAY WESTCOTT/POLITICO Debate turns 'scary' on debt 
 
 Washington’s frayed nerves showed through Monday amid tough talk on the right, a White House veto threat, canceled weekend passes and the top Senate Democrat likening default to a “very, very scary” outcome even for those “who believe government should be small enough to drown in a bathtub.” 
 
 “What will it take,” asked an agitated Majority Leader Harry Reid (D-Nev.), “for my Republican colleagues to wake up to the fact that they’re playing a game of political chicken with the entire global economy?” 
 
 Story Continued Below 
 
 House Speaker John Boehner confirmed a POLITICO report that he had met again privately with President Barack Obama at the White House on Sunday to try to get debt talks back on track. But ignoring Obama’s veto warning, Boehner will press ahead Tuesday with House votes on a revised debt ceiling bill that shows no sign of compromise on the spending and tax policy differences behind the crisis. 
 
 Indeed, with the Aug. 2 deadline exactly two weeks away, the House GOP is doubling down its bet with 10-year statutory spending caps intended to wring $5.8 trillion in unspecified savings from the government during the next decade — more than twice the $2.4 trillion debt ceiling increase that is allowed. And in his haste to act, Boehner will bring the so-called Cut, Cap and Balance bill to the floor under exactly the type of procedure he has said he abhors: limited debate and with no real review by any legislative committee. 
 
 The House “committee” most involved, in fact, is the Republican Study Committee, a fiscally conservative caucus within the larger Republican Conference. And as part of the RSC’s bargain with the leadership, the bill also makes any debt ceiling increase contingent on Congress first approving a balanced-budget constitutional amendment designed to make it harder to raise taxes in the future. 
 
 The administration was unsparing in its response, pushing back hard for fear of being boxed into a corner. 
 
 Obama’s press secretary, Jay Carney, mocked the bill as “duck, dodge and dismantle.” The formal White House veto statement took an almost lecturing approach: “Instead of pursuing an empty political statement and unrealistic policy goals, it is necessary to move beyond politics as usual and find bipartisan common ground.” 
 
 The measure was filed only on Friday, and the fast-paced maneuvering has caught some rank-and-file House Republicans off guard. But if the leadership prevails, as it now expects, Senate Republicans are demanding a crack at the same proposal. 
 
 “Two years of reckless spending and debt have brought us to the point of crisis,” Senate Minority Leader Mitch McConnell (R-Ky.) said in response to Reid. And McConnell welcomed the House initiative as “the kind of strong medicine Washington needs and the American people want.” 
 
 Behind the sparring, Reid and McConnell continue to work together, in fact, on their own fallback debt strategy — very different from the House bill. 
 
 Given the tortured tone of his floor speech, the Democratic leader rushed to point out to McConnell, “I didn’t lump all Republicans in one big bundle there.” But he warned that senators should expect a forced march up to the Aug. 2 deadline or beyond — until some answers are found.
– Exasperation is high on Capitol Hill, as the House and Senate barrel ahead with unrelated debt ceiling plans, neither of which resemble the “grand bargain” President Obama wanted. Today, John Boehner will hold a vote on his so-called “Cut, Cap, and Balance” bill, which calls for $5.8 trillion in unspecified cuts and a constitutional amendment requiring a balanced budget and making it harder to raise taxes. The White House mocked the bill as the “duck, dodge, and dismantle” measure, Politico reports, and has vowed a veto. The Senate is working on a bipartisan bill, but even there, nerves were fraying. “What will it take,” Harry Reid demands, “for my Republican colleagues to wake up to the fact that they’re playing a game of political chicken with the entire global economy?” Even if all goes according to plan, the Senate won’t vote on its compromise until July 29, giving the House just four days to pass it before Aug. 2—and there’s no guarantee it will, the Washington Post reports. Things are getting “very, very scary,” one top Senate Democrat said, even for those “who believe government should be small enough to drown in a bathtub.”