Englishmen look at the US budget process with awe. So does most of the rest of the world. Economic leaders at Versailles this week have other problems but may sympathize with President Reagan's declaration in California, May 29, that ''nothing in our federal government is more in need of an overhaul than a ridiculous procedure we have misnamed the budget process.'' He called it ''the most irresponsible, Mickey Mouse arrangement that any government body ever practiced.''
Budget failure in Congress gives President Reagan's prestige a setback just before the European summit conference. There is also genuine wonder in many countries on how America makes its system work. No other country has it.
The United States functions under the oldest continuous Constitution of any country at Versailles. Some 100 new governments were formed after World War II, but none adopted the American separation of power with the accompanying budget process. In the long run, the system has worked. But it has recently brought the threat of having no formal budget at all; then the country would run on a series of continuing resolutions, and it may develop this way in 1982.
''We are the only country,'' remarks political scientist Lloyd Cutler, a one-time White House counsel, ''where the legislature can vote a larger budget than the executive proposes.''
In England, budget introduction is partly ceremonial, since everybody knows that if the budget is adversely altered by so much as a farthing it constitutes a vote of no confidence and there will therefore be an immediate election. In Washington, by contrast, President Reagan introduced his budget last winter, it has dragged on since then, and now the House, after working four days and nights , finally rejected seven versions and left the whole matter in doubt.
In a parliamentary government the budget is the creation of a corps of authorities working toward an integrated plan and a responsible, coordinated program. In Washington, with the recent decline of political parties, the rise of special-interest political action committees, and the accelerated tempo of events, the budget process has become increasingly complicated under the separation of powers, leading to President Reagan's outburst.
In Washington White House counselor Edwin Meese III last week proposed major changes in the budget process which might transfer some power from Congress to the executive branch. He called for changes that President Reagan may explore in seeing how other democracies manage--a line item veto for the president, and a longer (two-year) budget cycle. He also thinks the executive branch spends too much time responding to congressional inquiries.
Mr. Reagan's European visit brings him in contact with other government systems. The British election lasts only about three weeks; in America the 1984 campaign has already begun. A four-year fixed term gives the President greater job security than most parliamentary prime ministers, but Mr. Reagan is aware that he must run a kind of permanent national popularity campaign.
A major task is to organize political forces to countervail against coalitions mobilized by departments, interest groups, and bureaus into what amount to sub-governments. According to political scientist Richard Rose, writing for the American Enterprise Institute, presidents spend the first year or two in on-the-job training where their first mistakes may come at the top. As Professor Rose puts it, ''Almost every writer about the contemporary presidency emphasizes the widening gap between what a president is required or expected to do, and the resources at hand.''
America remains the richest and in many ways most successful nation on Earth. New questions may arise, however, following Mr. Reagan's sharp attack on the budget process. Some note that public participation in every presidential election has declined since 1960 (only 51.1 percent in 1980); and that economic consensus is harder to get. There is the question about the budget. An unusual number of proposals for constitutional amendments are pending. Some blame the system itself.
Opinion divides: Many see only disaster if the US makes major changes in its revered instrument. Others note that Thomas Jefferson himself wanted the Constitution revised ''every generation.''