Slowly, but almost inevitably, a new idea is gathering force in Washington: a blue-ribbon, bipartisan commission--patterned after the Social Security, MX, and Central America commissions--to deal with the awful problem of the enormous federal budget deficit.

The commission idea emerges out of the frightening prospective volume of red ink over the next four or five years, and a recognition that the Reagan administration won't propose, and Congress by itself doesn't have the political guts, to raise taxes and cut spending sufficiently--at least until after the 1984 presidential election.

One of the most knowledgeable and influential congressional Republicans, the veteran Barber Conable of New York, said candidly at an economic conference in Vail, Colo., the other day that "in one way or another, we are going to have to deal with this issue outside the electoral process."

Conable fears that the current optimism about economic recovery is disguising the real sacrifices the public will eventually be called on to make through tax increases and social program reductions. "It can't be done with smoke and mirrors," he snapped.

He observes that "we're a crisis-activated governmental system. And there's no sense of crisis at this point, yet the crisis becomes more severe if we don't deal with fiscal imbalance fairly soon. And thus I do believe that while you would not expect the candidates for high political office to spend a lot of time going around spreading gloom and doom, somebody ought to be at least thinking about the types of measures that may be necessary if the deficit is going to be reduced."

Financial markets here and abroad now must operate on the assumption that at the earliest, it will be some time in 1985 (if at all) before politicians will deal with these critical issues. Until such time as that happens, record-high real interest rates that stifle businessmen's incentive to invest will haunt the U.S. and world economies.

The bipartisan commission idea is a way of bridging that gap in time, and offering some hope that a responsible solution might be put in place as soon as a new or reelected administration takes office early in 1985. The notion appears to have been floated first by business consultant Horace Busby, former aide to Lyndon Johnson.

Busby, one of the shrewdest political observers in this town, points out that given the fairly even division of power between Republicans and Democrats, "anything that comes through the system, anything that is done in Washington, has to be done on a bipartisan basis."

So long as the Republicans control the White House and the Democrats have a "lock" on the House of Representatives, Busby holds, "there is no longer any place for an obstructionist role on the part of either party."

Applying much the same logic, Alan Greenspan--who chaired the successful Social Security Commission--has called for an inter-governmental "summit" meeting to "defuse" the interest rate time bomb caused by continuing big deficits.

Greenspan's summit plan, a variation of a commission proposal, would bring together President Reagan, House Speaker Tip O'Neill, Senate Majority Leader Howard Baker, and the chairman of the key finance/tax committees of Congress in a series of private conferences "for the purpose of agreeing to a single solution to the deficit problem."

Busby's focused on the need to revamp the tax system (he favors taxing consumption rather than income). Washington lobbyist Charls E. Walker extended Busby's idea, circularizing 300 congressional and business leaders on Aug. 15 with a plan for a congressionally created "Commission on Spending and Taxes" to report back to Congress in January 1985 with specific tax and spending recommendations to deal with the deficit.

Busby's main theme is that the present tax system is "a failed system" that penalizes savings and punishes investment. He said that "Congressmen have found that they no longer can make points talking about 'tax loopholes' because everybody out there (in the middle-income brackets) is looking for loopholes."

In a telephone interview, Walker conceded that a blue-ribbon commission is not needed to come up with new ideas on how to cut the budget deficit. "There are plenty of ideas around on how to do it," he admits. But such a commission composed of key congressional committee chairmen of both parties, former Treasury secretaries, a couple of distinguished economists and political names of opposing political faiths could provide the necesary heat-shield to get unpopular measures through Congress.

Walker mentioned as possibilities Republican economist Greenspan and Democrat Walter Heller; Democratic "pol" Robert Strauss and Republican Drew Lewis; and as chairman, one of two former Treasury secretaries: C. Douglas Dillon or Henry H. Fowler. For maximum credibility, Walker would have the commission launched by congressional resolution, with appointments to it divided between the president and Congress. The hearings pursuant to the resolution would help establish the boundaries for the commission's work.

"The report would be rendered at the start of a new or holdover administration, a time which often marks the opening of a 'political window' through which governmental actions that would be almost impossible at other times may pass," Walker said.

Is there danger in yet another commission? Are we risking a degeneration into Government by Commission? Busby, Walker, Greenspan and Conable don't think so, arguing that with fractionated power, some sort of political truce is inevitable and necessary. And former Economic Council chairman Paul McCracken notes there's nothing basically new in the commission idea: it was a citizens commission, after all, that wrote the Constitution.