The Carter administration may give its all-important blessing next week to a federal labor-management package that would give unions tremendous new clout and give unorganized civil servants important incentives to join unions.

If the proposal is approved by the president, as expected, it would revamp the present "adverse action" appeals system that agencies and employes now use in demotion and dismissal cases. In effect, the proposal would increase the "survival" odds of a government worker in danger of losing a job or a pay grade.

The proposed legislation would continue the union shop and ban on strikes against the government. It also would continue to deny unions the right to bargain on pay raises.

In return, the legislation would give federal unions a labor-management code set in law - rather than by presidential directive - and permit a system through which employes could choose between the regular appeals system or an independent arbitrator to decide the outcome of adverse action cases.

Under the present appeals system, U.S. workers threatened by adverse actions generally lose when their agencies set out to fire or demote them. Giving workers the right - through their union - to go to arbitration would increase their chances of winning and holding on their job or grade.

Administration endorsement of the bill would almost guanantee congressional approval. And it would spur employes into joining unions for their own protection. The plan would permit unions with "Exclusive" bargaining rights to negotiate for the arbitration feature, something they cannot do now.

Under the proposed plan, federal unions would have to defend members and nonmembers alike (just as they do in the private sector). But it would be to an employe's advantage to join a union, or at least vote for one to be bargaining agent in an agency.

The package could do as much to increase union membership as did the order of President Kennedy, which set up payroll dues deductions, an action that triggered rapid expansion of federal union membership in the early 1960s.

If the proposal comes off, it would go a long way toward diffusing the explosive situation set up by the president's decision to limit this October's federal-military pay raise to .5 percent.

Such a bill also would save the political bacon of Kenneth Blaylock, president of the American Federation of Government Employes. Blaylock has been under fire from within AFGE, the biggest employe union, for generally endorsing the Carter administration's civil service reform plan. Most unions have opposed it, on ground that it gives management too much power over rank-and-file workers.

"Ken has been playing a relatively dangerous game," a top Carter adviser said yesterday. "But the stakes are high. If he can get White House backing for this, he will have something the unions have been unable to get for 20 years."

If the labor-management bill doesn't get White House backing relatively soon, the AFGE is expected to withdraw its general support for the civil service reform plan. That could hurt the proposal in Congress, and also prove a source of embarrassment to Blaylock when he seeks reelection this summer.

Pay Flap: The four unions represented on the Federal Employes Pay Council are holding a press conference today, most likely to announce that they are leaving the advisory group. The four group, AFGE, the AFL-CIO's Public Employes Department, National Treasury Employes Union and National Federation of Federal Employes, have all blasted the federal pay freeze and will go to Capitol Hill to ask Congress to overturn it.

Jobs: Bureau of the Public Debt is recruiting computer programmers at Grades 7 through 11. Call Harris at 447-1408 . . . Interstate Commerce Commission needs a personnel management specialist (status) GS12 or 13 and a part-time computer technician, GS 5. Call 275-7414.

Hazardous Material Safety Specialist: National Transportation Safety Board has a temporary Grade 9 through 12 vacancy.Call Brown at 472-6167.

American Arbitration Association has a new member of the board, Emmet Andrews of the American Postal Workers Union. Andrews, who belongs to the AFL-CIO's executive board, will serve on the AAA, which is a private, nonprofit group that helps to settle labor disputes.