Senate budget-cutters lost a skirmish yesterday as the Agriculture Committee proposed a billion-dollar increase in the food stamp program for fiscal year 1980.

After a debate that pitted concern about inflation against concern for the poor, the committee agreed, by a one-vote margin, to recommend eliminating the spending ceiling that Congress imposed in 1977 in an effort to limit the program's rapidly growing costs.

Specifically, the committee sent the Senate Budget Committee a recommendation that $6.9 billion be spent on food stamps in fiscal 1980, a 19 percent increase from the current level of $5.8 billion. The recommendation would exceed the budget ceiling of $6.18 billion established in the food stamp "reform" law of 1977.

Although the committee's action came down to a question of dollars, the real issue in yesterday's debate involved the question -- clearly a painful one for both sides -- of whether federal benefits to the poor should be cut as part of the effort to reduce the federal deficit.

Democrats, who generally supported the budget increase, and Republicans, most of whom favored adhering to the 1977 ceiling, both struggled with a dilemma: increasing the food stamp program to help poor people deal with inflation would exacerbate the problem of inflation.

Sen. George McGovern (D-S.D.), the most ouspoken supporter of the budget increase, said food stamp benefits would have to be cut for all recipients if the 1977 ceiling were retained. That's the wrong way to deal with inflation, if you ask me," McGovern said. "You give the poor less when food costs more."

Sen. Richard Lugar (R-Ind.), who favored holding to the spending ceiling, took issue with McGovern's projections, saying retention of the ceiling might not force an immediate cut in benefits. But Lugar's chief argument was that increasing benefits would undermine the fight against inflation.

"If we indew these large spending programs to increase with our projections for next year," Lugar said, "we are in the position of indexing inflation right into the budget."

After 40 minutes of debate, the committee rejected, by a vote of 9 to 8, a Lugar motion that would have prohibited spending in excess of the $6.18 billion ceiling. The recommendation for the new budget figure of $6.9 billion was then approved by a voice vote.

The committee's action yesterday was a recommendation to be sent to the Budget Committee for preparation of the year's first budget resolution. To eliminate the spending ceiling will require specific legislation. Yesterday's vote indicates that the committee will approve such a bill.

MeGovern said yesterday the budget increase was likely to pass the Senate, because "we generally do better on food stamps on the floor than in this committee." The House has not taken up the question yet, and it is not clear how that body will respond to the effort to increase the ceiling.

The $6.18 billion ceiling was a House initiative in 1977, but it was accepted without much quarrel in the Senate because, at that time, nobody expected the food stamp budget to exceed that figure. But the rapid increase in food prices -- twice as high as economists were predicting in 1977 -- changed those expectations.

The food stamp program, which provides about 16 million people an average of $28 per month worth of coupons that can be used as money in food stores, has grown enormously in the past decade.

In 1969, there were about 3 million recipients and the annual budget was $272 million. Since then, the budget has increased by a factor of 25 partly because of the increase in recipients and partly to offset the inflation of food prices.

The 1977 law, in addition to imposing the budget ceiling, tightened the rules governing eligibility requirements for the stamps. At yesterday's hearing, the committee chairman, Herman Talmadge (D-Ga.), was discussing one such rule, which made it harder for people who voluntarily stop working to get stamps.

"How's that rule on the loafers working?" Talmadge asked Department of Agriculture officials who were present. The embarrassed bureaucrats had to admit that it wasn't working -- because they have not yet completed the regulations to liplement the 1977 law.