The House yesterday approved $1.2 billion for congressional operations next year after a day of partisan trench warfare during which Republicans tried to squeeze spending for everything from paper clips to the people who operate the House's automatic elevators.

Their only success was a $2.3 million reduction in proposed funding for the Congressional Research Service of the Library of Congress, which is more closely related than most of their other targets to the ostensible business of the House: legislation.

Other spending, including $107 million to pay for an election-year outpouring of postage-free congressional mail, escaped unscathed, although it took a little arm-twisting at the last minute to prevent a 5 percent reduction in the $67.2 million allotment for members' office expenses.

While Republicans contended that Congress should set a model for fiscal restraint by cinching its belt, Democrats, joined by Rep. Jerry Lewis (R-Calif.), ranking Republican on the Appropriations subcommittee for the legislative branch, contended that it already was doing so.

"Every member of this body can report to his constitutents that fiscal responsibility begins at home--here in the halls of Congress," subcommittee chairman Vic Fazio (D-Calif.) said. The bill calls for a spending increase of 1.4 percent, considerably less than anticipated inflation, Lewis added.

At one point, Rep. Henry B. Gonzalez (D-Tex.) took offense at suggestions that the House is abusing its free mailing privileges in election years. It just so happens that the mail sacks overflow in even-numbered years, responded Rep. Duncan L. Hunter (R-Calif.), noting that the House is planning for 840 million pieces of mail next year, nearly double this year's volume.

Then there was the perennial issue of the patronage employes who operate the automatic elevators.

Among other things, the situation is hard to explain to visiting constituents, Republicans complained. But Fazio said the elevator force already had been cut from 152 to 44, and contended that the proposed cutback would mean firing 14 people, including "students, senior citizens and severely handicapped persons."

The bill includes $720 million for congressional operations and $491 million for related agencies such as the Library of Congress, Government Printing Office and General Accounting Office. Senate expenses, expected to amount to about $270 million, will be added later by the Senate.

As the House was fighting over its own money, its Appropriations Committee approved a $34 billion spending bill for farm and food programs that, like two of four other bills already approved by the committee, is drawing threats of a presidential veto.

Although the bill's total cost is slightly less than the administration's request, it underfunds some programs mandated by law, such as food stamps, which would get only enough money for 11 months. Additional appropriations would be required later in the year unless Congress goes along with administration cost-cutting proposals, which is considered unlikely.

But the measure was approved unanimously, by Republicans as well as Democrats, despite a warning from Office of Management and Budget Director David A. Stockman that he would "not be able to recommend to the president that he sign this bill in its present form."

"Facts are facts . . . , farmers are in trouble," Rep. John T. Myers (R-Ind.) said.

Meanwhile, Democratic leaders said they will start polling House Democrats next week on proposals for modifying the 10 percent income tax cut scheduled for July 1, including caps of $500 and $700 as well as repeal, deferral or phase-out of the tax cut.

Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) said he hopes to have a tax bill passed and sent to the Senate by June 20. Senate Republican leaders, although they oppose any tax increases, agreed to a vote on the issue as the price for passage last month of legislation extending the debt ceiling.