CONGRESS WON'T be able to agree on a workable budget resolution until it decides on the size and shape of a tax increase. What is not lacking, however, is fairly wide consensus that a substantial tax increase is needed soon.

The House budget resolution already calls for a $30 billion increase starting next year. So does the tentative budget resolution voted last week by the Senate Budget Committee. And most of the president's economic advisers treat the "standby" tax increases proposed in the president's budget as if such increases-- or their equivalent--were a foregone conclusion.

The trouble is that no one seems ready to propose a tax package that could command both congressional and presidential support. "Speechless: stronger letter to follow," was the reaction of Sen. Robert Dole to the news that the budget resolution called upon his Finance Committee to raise $30 billion. And while the House budget resolution seemed tailored to a simple rescission of this July's tax cut, the president has vowed to veto such a measure. Many members, noting the apparent fragility of the current recovery, are also wary of forgoing the expected stimulus.

Most economists would agree, however, that whatever help may be gotten from another tax cut would be far outweighed by the short- and long-run economic damage that would come from rising interest rates. And interest rates will surely rise if the Federal Reserve and financial markets see enormous budget deficits on the horizon. What sort of tax compromise might give prompt assurance that--with election-year politics in the offing--the budget deficit will not be left spinning wildly out of control for the foreseeable future?

Any kind of tax increase will meet opposition on either practical or theoretical grounds. Closing loopholes, for example, is certainly the best way to raise taxes in theory. But it calls into action all the well-heeled lobbies that stand guard at the door of each tax shelter. Putting off the July tax cut or repealing future tax indexing would be easier. But both actions would hit hardest the lower and middle tax brackets that have gotten precious little from the Reagan tax cuts so far.

George Perry of the Brookings Institution offers a solution with both theoretical and practical merit. Why not, he says, take seriously the president's budget proposal for a surcharge on income taxes and an excise tax on both foreign and domestic oil? A surcharge would make high-bracket taxpayers share more of the burden than would rescinding either the July tax cut or indexing, and the oil excise tax has merit apart from revenue raising.

True, the idea of a "standby" tax is too hokey to reassure the financial markets, and 1986 is too late to put the new taxes into law. But Congress could remedy both these defects by making the tax increases certain and starting to phase them in next year. Throw in a few badly needed reforms and you'd have a bill that could and should command the support of both Congress and the president.