Senate conferees held firm in their demand for big defense spending increases last night as Senate Budget Committee Chairman Ernest F. Hollings (D-S.C.) likened President Carter to Neville Chamberlain, the pre-World War II apostle of appeasement.

After nearly a week of preliminary skirmishing over their conflicting approaches to a balanced budget for 1981, House and Senate budget conferees remained far apart on the key issue dividing them: guns vs butter.

"We're a long way from home," said House Budget Committee Chairman Robert H. Giaimo (D-Conn.) as the conferees wound up a 13-hour session with a $3.4 billion difference in their proposals for defense spending.

They started with a difference of $7.8 billion; the House defense proposal was $147.9 billion and the Senate's proposed military outlay was $155.7. Most of the give was on the part of the House, which reluctantly agreed to cut social spending programs in order to reach a compromise on defense. By the evening's end, the House had agreed to increase its plan for defense by $4.1 billion, while the Senate came down by $300 million.

While an impasse was not yet at hand, some House conferees warned that further domestic cuts might jeopardize the budget resolution in the House. "If they go any lower than this, they've lost me," said Rep. Paul Simon (D-Ill.).

In previous years, Congress would have responded to pressures for higher defense spending, such as those that arose from the Soviet invasion of Afghanistan, by increasing the deficit. But this year both houses, joined by President Carter, are committed to balancing the 1981 budget, meaning that any increases for defense must be offset by cuts in social programs. The Senate is pushing for such cuts, while the House is trying to resist them.

In its last offer last night, the Senate, while resisting further concessions on defense, offered to give up its demand for $700 million to continue the program of revenue sharing with states. This would effectively kill revenue sharing with the states.

Earlier in the day, in a strong appeal for higher defense spending, Hollings said Congress has "decimated defense" in recent years, and raised the specter of Chamberlain, the British prime minister during Hitler's early aggressions in Europe, in criticizing Carter's foreign policy. He said that when Carter kissed Soviet Party Chairman Leonid Brezhnev last year he probably thought he was reflecting public opinion "just like Chamberlain." Said Hollings: "Chamberlain didn't think he was an appeaser. He thought he was representing public opinion. Jimmy Carter thought he was reflecting public opinion."

Hollings said the military is facing a crisis in equipment and personnel, including pay levels that force some service personnel to go on food stamps. He said that, discounting inflation, the defense budget has not increased since 1960.

In response Giaimo said the country must balance domestic and defense needs and fight waste in the Pentagon as well as social agencies. "We're not strengthening defense when we waste money on the wrong kinds of defense," said Giaimo.