Federal union leaders blasted yesterday the president's decision to limit an October civil service and military pay raise to 5.5 percent. They warned it could trigger serious work slowdowns in key government operations and cost Carter labor support if he seeks reelection.

Although he rejected the idea of wage-price controls for the private sector, the President said yeaterday he would ask Congress to hold an upcoming catch-up-with-industry pay raise for 3.2 million federal and military personnel to 5.5 percent. Federal officials said that normally the so-called "comparability" raise might have been 6.5 percent or more.

Kenneth T. Blaylock, president of the 300,000-member American Federation of Government Employees Union, said the idea of mandatory wage controls for civil servants was "disgusting" and would not stop inflationary increases in wages and price in the private sector.

Blaylock, a member of the AFL-CIO executive board predicted that many AFGE members holding important service, safety and support jobs in agencies would react later this summer with a "slowdown."

Although strikes and slowdowns are illegal in government, federal officials admit that a strict adherence to production standards - called work-to-rule - could, in fact, slow down many functions without violating the law.

"Kenneth T. Lyons, president of the National Association of Government Employees, had a brief but to the point "Nuts To You" comment for the White House plan to hold down the 1978 federal-military raise.

"It is ironic that Mr. Carter could hardly contain his elation a short time ago when the nation's coal miners settled for increases totaling 32 per cent for the next three years," Lyons said, and then turn around and offer "peanuts" to civil servants. "My message to the White House is that our members are getting damn tired of being drafted for the front line in these annuals 'wars on inflation,'" Lyons said.

National Federation of Federal Employees president James Peirce said the White House has "no grasp of reality" if it thinks mandatory federal wage controls will inspire labor and industry to voluntarily control their own increases.

Peirce said federal workers already have fallen 18.5 per cent behind the cost of living since 1972, mainly because Presidents Nixon and Ford cut back their catch-up-with-industry raises.

Vincent Connery, president of National Treasury Employees Union, said the Carter administration is looking like its "Republican predecessors by simply designating federal employes as sacrificial victims who must set an example . . . for others to follow."

All the union leaders said they were considering resigning from the Federal Employees Pay Council, which is designed to advise the White House on government salaries. Blaylock said the system "obviously doesn't work" and said he would recommend to his executive board today that AFGE walk off the council.

Blaylock said the president's growing tendency to "back away from promises" made to various groups is "alienating every segment of the society that elected him." Asked later if he though Carter was looking like a one-term president, the AFL-CIO leaser said: "He is to me. Damn right."

Congress will have a chance later this year to overturn the 5.5 per cent federal pay raise and order a larger "comparability" increase for government white collar workers. But since congressmen themselves will get the same increases, observers believe it is unlikely that they would vote the higher increases just one month before the elections.

Federal Highway Administration's William R. McCallum retired last week after 42 years with the government. He had been director of the office of program and policy planning since 1974.