House Minority Leader John J. Rhodes (R-Ariz.) said yesterday he has "grave reservations" about any constitutional amendment dealing with the budget, even one that would only limit federal spending.

The statement found Rhodes disavowing a resolution adopted by Republican Party leaders at a meeting in Easton, Md., Sunday. The resolution called on Congress to consider immediately a constitutional amendment to "limit federal spending."

Rhodes was among a group of Republicans at the meeting who successfully fought off attempts to endorse a stronger resolution calling for a constitutional amendment to require a balanced federal budget.

He admitted that those who agreed with his position were "probably a minority" among House and other Republicans, but predicted, "I won't be [in a minority] when people go down the road and get to the bottom line."

The bottom line, according to Rhodes, is that there is practically no way to make such a constitutional amendment workable.

He said an amendment calling for a balanced federal budget would be unworkable because there's difficulty in defining what the budget is. He cited "off-budget expenditures" -- money spent by the government that does not appear as a regular budget item, such as subsidies for the Postal Service or financing for federal housing programs. "It would be so easy to endrun it," Rhodes said of a balanced budget amendment.

Rhodes said a constitutional amendment to limit spending "could be tied to the gross national product or the consumer price index," but he said those are not precise terms and he questioned whether they would have "meaning in five years or 50 years."

"Suppose we don't have a balanced budget or stay within a constitutional spending limit. What's the remedy? What are the sanctions? Is the Supreme Court going to take over the operation of government?" Rhodes asked.

"If we were passing a law I wouldn't worry too much about it. When you talk about amending the Constitution I do have grave problems and grave reservations. There's no shortcut to the type of political action the republic requires."

Rhodes said the remedy would be to "elect more Republicans" who would support a balanced budget or to adopt amendments that would cut spending in the budget.

He criticized Democrats for making spending cuts more difficult by demanding that they be specified by program rather than allowing an unspecified cut in the total budget.

Rhodes also criticized Attorney General Griffin B. Bell's contention that if a constitutional convention were called it could be limited to the balanced-budget issue. Twenty-five states (of the 34 required) have passed petitions calling for such a convention if a balanced budget amendment is not adopted by Congress. "Every other lawyer I know doesn't believe it's possible to limit the scope of such a convention," Rhodes said. He raised the specter of the convention dealing with all sorts of controversial issues, from the Equal Rights Amendment and abortion to gun control.

Meanwhile House Judiciary Committee Chairman Peter W. Rodino Jr. (D-N.J.) is expected to announce this week that his committee will hold hearings on a constitutional amendment to balance the budget or limit spending.