Washington — For American taxpayers now confronting their 1040 Internal Revenue Service forms with only two weeks to go, it's little comfort to know that most of Congress can write off one-third of their salaries and not risk a tax audit.
Senate and House members can now take $75 off for Washington living expenses for every day in the legislative year, without giving the IRS any documentation. By that system, a lawmaker can subtract $19,000 from his taxable income.
By some estimates, a member of Congress with a lavish life style could itemize expenses and wind up getting his entire federal paycheck tax free.
Despite a barrage of criticism ever since Congress slipped the law through last December, the tax break survived a frontal attack this week. And as Congress packs its bags for the Easter recess, there is little chance that it will repeal the benefit before the April 15 deadline for filing income tax forms.
Dealing with issues concerning their own pocketbooks has always brought out strong emotions and devious methods among Congress members.
Item. Alaska Sen. Ted Stevens, Republican whip, his face flushed, stood on the Senate floor this week and delivered a diatribe against Washington, D.C. ''I detest it,'' he told his colleagues. No town has worse crime or schools, he said by way of evidence that he considers Alaska his home and should be given a tax break for having to live in a city which he allowed was the worst possible choice for a capital.
At best, a member might save $6,000 to $7,000, said Senator Stevens March 30 in his defense of the tax break. He charged lawmakers who oppose him with using ''demagoguery.'' (The ''demagogues'' lost, as a proposal to repeal the new tax deductions failed by a 48-to-51 vote.)
Item. The leaders of both parties in Congress maneuvered the tax measure through last December by slick parliamentary moves. They attached the measure to an obscure miners' benefits bill and passed it in the House by voice vote, on the premise that House members would not approve it in a recorded tally.
''It was a lousy, sneaky way that they did it,'' says Rep. Patricia Shroeder (D) of Colorado. She voted yes on the bill but didn't know the congressional tax cut had been attached. Now she is one of several members who are filing discharge petitions to repeal the tax law.
However, discharge petitions are almost never successful. House Republican leader Robert H. Michel of Illinois writes off the effort as ''a lot of posturing.''
At the heart of the dispute is congressional embarrassment over raising its own salaries. Members, both senators and representatives, earn $60,662, but many feel they are paid too little. Their last raise was in 1979.
Sen. William L. Armstrong (R) of Colorado, who spearheaded the move this week to repeal the tax law, criticized the law for treating Congress members differently from other taxpayers. He is calling for a new law that would allow the lawmakers to take the same deductions that others now receive.