Government workers would be protected from virtually all forms of pay and grade cuts if Carter aides and House leaders agree to merge two different demotion insurance packages into one bill.

The two proposals are designed to make reorganization of the bureaucracy less painful to the people who must implement it, and to protect civil servants from painful midcareer demotions and pay cuts because of old classification errors.

Palan number one is the bill by Chairman Robert N.C. Nix (D-Pa.), who heads the Post Office-Civil Service Committee. Hearings have apparently been concluded on the Nix bill by the Compensation and Employee Benefits subcommittee chaired by Rep. Gladys N. Spellman (D-Md.).

That bill would shield government workers from downgradings resulting from intensified job audits that agencies are now making. The idea is to give workers lifetime pay and grade retention rights if their job is downgraded through no fault of their own.

The job itself would be earmarked for cutback to the proper level, but that wouldn't happen until the incumbent left the job or the government. The nix bill, however, does not deal with shakeups that can and will happen as agencies are merged or otherwise reorganized along lines already outlined by the President.

Plan No. 2, from the Carter camp, doesn't deal with the issue of jobs downgraded because of classification errors. They are interested in reorganization and want job guarantees (two years in grade and no pay loss) for employees hit by reorganization shakeups or reductions in force.

Under the Carter plan, employees would remain in grade for two years after the job had been downgraded. Pay raises for those downgraded workers would be half the regular October adjustment given other federal workers until they gradually reach the salary level of their downgraded job.

The idea of a broader protection package - merging the Carter and Nix proposals - is being seriously considered. Insiders say there is a good chance the plans will be lumped together and be ready for a House vote sometime after the August congressional recess.

If that happens, it would constitute a substantial job demotion insurance package for federal workers that is assured of support in the House, and of White House backing.

Merging the two plans would mean federal workers would be protected for life, in effect, if their jobs are downgraded for reasons of reclassification. And it would give partial grade and salary protection for workers hit by reductions in force or reorganization-related shakeups.

Studies by the General Accounting Office and some congressional units have shown that as many as 30 per cent of the jobs in some offices and agencies are overgraded and therefore ripe for reclassification and downgrading. Critics point out that the studies were made in known problem areas, so that doesn't mean that 30 per cent of the federal work force is overgraded and overpaid.

Even if the government-wide error rate is half the 30 per cent estimate, that still would mean that thousands of federal workers over the next few years could expect to have their jobs downgraded after agency audits.

Nobody yet knows the impact of reorganization on the grade structure of federal agencies, but mergers streamlining and abolition of offices and work would hit hundreds of workers directly and have wide impact as senior employees who are downgraded "bump" through the system, displacing less senior workers.

If the two demotion insurance plans are merged, it won't make for an absolutely painless reorganization, but it would give workers much better job and pay guarantees than they now have.

It would certainly minimize inhouse opposition to Carter plans to streamline government, and permit tough reclassification of jobs to proceed since the actual blood-letting via downgrading would be delayed until people already at those grade levels had left or retired.

Herman Staiman, chairman of the Appeals Review Board, will retire at the end of the month.