President Reagan's refusal to accept defense spending limits set by Congress for fiscal 1984 and 1985 set off a storm of Republican protest yesterday and House and Senate GOP leaders, in a rare open break with the president, said they will ask him to reconsider his position.

The fight broke out amid mixed signs as to Congress' new mood on defense spending. On the one hand, the House passed a final money bill for this fiscal year that gives the Pentagon $2 billion less than it requested, while also refusing $115.5 million in foreign military assistance, and the House Appropriations Committee recommended almost $1 billion less for the military in fiscal 1983 than Congress left room for in its budget.

In both actions, domestic spending was slightly increased while Reagan's big proposed buildup in defense was modestly cut. He appears to want to move in the opposite direction.

The House also voted last night to shave 1 percent--about $1.7 billion--off a $177 billion defense authorization bill for next year.

But then it passed the $175.3 billion measure, which even in its shaved version was an impressive victory for the president on defense policy. The bill's easy passage, 290 to 73, indicated that, while there is still disagreement over exactly how large the defense buildup should be, the president has largely prevailed on the basic point that there should be such a buildup even as there is retrenchment on the domestic side. Details on Page A4.

Reagan triggered yesterday's angry response--intense even among his strongest supporters--when he told a news conference Wednesday night that, while next year's defense figures were now nailed down, he did not feel bound to keep defense spending for the two following years within limits of the budget that Congress adopted and he embraced only a month ago.

"How the hell is he going to spend more than we say he can?" asked House Minority Leader Robert H. Michel (R-Ill.) after a party caucus during which several members complained that Reagan was ignoring curbs on military spending while demanding that Congress toe the line on domestic spending.

Describing himself as "disappointed," Senate Majority Leader Howard H. Baker Jr. (R-Tenn.) said Reagan's news conference assertion could undermine support for budget compliance in Congress--a point also made by Senate Budget Committee Chairman Pete V. Domenici (R-N.M.).

The fear of some critics was more specific: that Reagan, by agreeing to abide by budget totals but reserving the right to adjust component parts, intended to press in 1984 and 1985 for more defense spending at the expense of deeper reductions in social welfare programs, which are already sustaining severe cutbacks.

A letter was being circulated for signatures in the House by Rep. Olympia J. Snowe (R-Maine) asserting that any breach of defense limits could "unravel the progress" already achieved in cutting federal spending.

"Reductions in federal spending. . . must be shared by each sector of the federal bureaucracy if we are to gain control over our economic destiny," the letter said. "Defense spending must not be sacrosanct." An aide to Snowe said she had gotten 34 signatures by late afternoon.

While Snowe is a moderate "Gypsy Moth" who has questioned defense spending levels all along, criticism came from more conservative quarters as well. Reagan's position "doesn't help our problem" of getting Congress to comply with the specific spending cuts called for in the budget, said Rep. Delbert L. Latta (R-Ohio), ranking Republican on the House Budget Committee. "They the White House might want to rethink that."

An aide said Michel wrote a note to Reagan "conveying the sentiments of our members," while Baker talked with White House chief of staff James A. Baker III and asked to talk personally with the president, whom he had still not reached by early evening. An aide said Sen. Baker would ask Reagan to review his position, and Michel said he intended to do the same.

Baker and others expressed bewilderment as to why Reagan did what he did, especially now. There has been a dispute within the administration for months over whether Reagan should pare back his defense buildup to help reduce future deficits and win support for his other budget proposals.

Reagan seemed to agree to do this in endorsing the congressional budget resolution. That was an internal victory of sorts for budget director David A. Stockman and James Baker, who had urged such accommodation. But conservatives led by Defense Secretary Caspar W. Weinberger--reportedly aided by national security adviser William P. Clark--continued to press Reagan to stick with his original figures for defense for 1984 and 1985. And in the midyear budget review just completed, in which these issues came to a head, the conservatives apparently prevailed.

Reagan was said yesterday to have gone to the unusual lengths of sending a firmly worded letter to Stockman providing "final guidance" and settling the dispute.

The Pentagon's loss of $2 billion from requested spending for the rest of the current year ending Sept. 30 was contained in a supplemental appropriation bill for nearly $14 billion that did, however, include funds for military as well as civilian pay raises granted last October.

What was refused were assorted military expenditures that either had not been authorized or could wait until next year, according to Rep. Silvio O. Conte (R-Mass.), ranking Republican on the Appropriations Committee.

The Appropriations Committee recommendation to allow $1 billion less than what was budgeted for defense next year was in the form of guidance to its subcommittees. Rather than go along with the $238.6 billion ceiling for defense in the budget, the Appropriations Committee advised its defense subcommittee to stay within $237.6 billion.

The lower target is not binding but serves as a preliminary division of the budget among major categories of spending. While defense lost, agriculture, energy and water development and the District of Columbia were among the gainers. The increase for agriculture included additional funds for food stamps.