House and Senate conferees broke an impasse over abortion funding and agreed to stopgap funding last night to keep money flowing into the federal bureaucracy. But their abortion compromise ran into opposition in the Senate.

The House approved the measure, 292 to 100, shortly after 1 a.m., just missing the midnight deadline for expiration of the government's spending authority for the new fiscal year.

But a group of Senate Republicans led by Minority Whip Ted Stevens (R-Alaska), who had earlier talked about filibustering, proposed to liberalize anitabortion restrictions in cases of rape or incest that the conferees had adopted, meaning that, if the Senate went along, the whole package would have to be sent back to the House. The House, however, had adjourned for the night.

The compromise was reached when the House conferees agreed to go along with Senate demands to continue Medicaid funding of abortions in cases of rape and incest, but only on condition that the acts be reported within 48 hours. Objecting to that condition, Stevens said, "I did not come to the Senate to be bossed by the House."

Steven's proposed modification in the conferees' agreement would permit abortions arising out of rape or incest if the acts were reported within 48 hours from confirmation of a pregnancy instead of the act itself, giving the woman a longer period in which to report to authorities.

The dispute became so intense earlier in the evening that the conferees broke up in deadlock, despite a complaint from Sen. Patrick J. Leahy (D-Vt.) that they looked "like a bunch of idiots," to thwart the orderly running of government because of an antiabortion rider affecting only a few cases over the next few months.

Earlier in the day, the conferees had agreed on 47 to 48 disputed issues -- everthing except the habitually intractable issue of abortion funding.

"We capitulated to you for the last time . . . if you don't take this, you can go home as far as I'm concerned," snapped Stevens as the House conferees refused to back down from their insistence on Medicaid abortion funding only when a woman's life is at stake.

Current law permits federal funding of abortions in cases of rape or incest as well as jeopardy to a woman's life. The Senate voted to continue abortion funding for rape and incest, while the House voted to stop it.

The Senate agreed with the House, however, to let states adopt even more restrictive antiabortion spending rules than Congress has approved -- a concession that the Senate conferees contended should be enough to satisfy the House.

The race with the clock was necessitated by the fact that money to run government runs out when the fiscal year ends Sept. 30, unless Congress has passed appropriations bills for the new year. This year's Congress, flinching from tough election-year choices, has finished action on only one of 12 money bills.

The stopgap measure is intended to continue funding the government at current or slightly increased levels through Dec. 15 -- giving Congress enough time to take a month off for campaigning and then to return to pass the appropriations bill, or extend the deadline for the interim financing. p

Although Congress often bumps into, or rolls past, deadlines for financing government agencies, its problems this year were compounded by an attorney general's ruling that any unfunded agency must begin to shut down as soon as its appropriations run out.

But here was a demonstrable lack of panic in Congress about the latest exercise in appropriations brinkmanship, apparently born of an abiding faith in the bureaucracy to survive just about anything.

Before a late afternoon recess to prove for a compromise on the abortion issue, the conferees agreed to fund programs through Dec. 15 at their 1980 level or at levels proposed in House-passed appropriations bills for 1981, whichever is lower. A major exception was the Pentagon, which could spend at the higher level proposed by the House for 1981, meaning $20 billion more than it is spending now.

In a partial reprieve for the controversial public service jobs program, the conferees agreed to cut it by $64 million rather than the $550 million that the Senate proposed and to shift the money to another employment program for young adults.