President Carter's decision to hold down federal pay raises provoked immediate, hostile reaction from federal employes, their allies in Congress and top labor leaders who hinted strongly that they might retaliate by withdrawing support for his reorganization of the civil service system.

This means that the most important proposal in Carter's anti-inflation message is already in jeopardy and that he has further imperiled his civil service reform program, one of his administration's major commitments.

Congressional and federal employe reaction focused on the belief that federal workers were being unfairly singled out to absorb the first loss in pay in an anti-inflation drive that they believe is doomed to failure because the private sector will not be forced to follow suit.

"If he (Carter) could hold the other folks down, it would be worth it," said a Civil Service Commission employe, who asked not to be named. "But it hasn't worked in the past. I don't think it's fair to single us out. My raise doesn't cause inflation. My raise is supposed to reflect inflation."

A number of federal workers cited the recent United Mine Workers settlement, engineered by the administration, which provides for an increase of about 30 percent over the next three years. "Is that an example of how the private sector is going to show restraint?" asked a Housing and Urban Development employe.

Rep. Herbert Harris (D-Va), whose district includes thousands of federal employes said he will introduce a resolution in Congress reversing the president's decision and giving federal employes full "catch-up" raises that would bring their salaries up to a level that is comparable to privare industries.

Federal budget experts have estimated that a raise of 6-to-6.5 percent is necessary to achieve comparable pay levels. Although the president, as the top federal boss, is mandated by Congress to maintain comparable pay levels between the public and private sector, he has the leeway to decide through a complicated formula what the comparable pay level should be.

Harris and other opponents of the pay cap reiterated their intentions to push for pay bargaining rights for federal employe unions if the president undercuts the principle of comparability.

Carter's 5.5 percent payraise limit will cost the 300,000 federal white collar workers in the Washington area an average of $206 per year, or $7.92 per (two-week) pay period, compared with 6.5 percent "comparability" raises, according to civil service pay experts. The figures will be slightly lower nationally, because of average pay is lower than the Washington area's annual average of $20,570.

Federal workers in their offices yesterday greeted with a mixture of clenched teeth, stiff upper lips and shrugs of helplessness the news that their president had drafted them into the front lines of his assault on inflation.

Some declared themselves unfit for duty due to battle fatigue. "I don't care any more," said Grace DeAnna, mother of four, administrative assistant in the Department of Health, Education and Welfare.

She said she had been through this cycle before: "We forgo a raise, prices go up anyway; we forgo another raise, prices go up again. Even with the raises, we don't keep up with the prices."

Some federal workers said pointedly that they are too busy working to take time to worry about the president's decision. A few said they backed the president's decision to "bite the bullet," and one midlevel worker in the Medicaid Bureau shrugged and said, "I feel woefully overpaid already."

On the subject of Carter's civil sevice reorganization plan, which he considers essential to cutting back on government waste, administration spokesmen said they hope it remains separate from the issue of the pay cap.

However, union spokesmen indicated yesterday that they are "rethinking" their already tenuous support for the civil service changes.

The administration had promised strengthened bargaining rights for unions in exchange for conditional support for its reorganization plan from the largest federal employe union, the American Federation of Government Employees. Backed by the lobbying clout of the AFL-CIO, its support was considered crucial to Carter's civil service changes.

"Were planning to continue our negotiations (on civil service changes involving collective bargaining) and hope they (union leaders) to do too," said an administration spokesman.

An AFGE spokesman indicated yesterday, however, that the president's pay cap decision "throws a new light on our position" on supporting civil service overhaul. He said union leaders will meet to plan a unified strategy.

Jerry Wurf, head of the American Federation of State, County and Municipal Employees, called Carter's anti-inflation plan "silly symbolism that will have no impact on inflation."