Legislation to protect federal workers from no-fault demotions and downgradings is alive and well on Capital Hill.

Insiders say the House Post Office Civil Service Committe will begin "mark up" (final consideration leading to committee approval) the third week in May. The Carter administration supports the proposal which would protect employes from demotions caused either by reorganizations or the discovery that their jobs are improperly classified.

Under the bill, thousands of workers who have suffered the so-called no fault demotions since January, 1977 would also have their grades restored. That would go for demotions for both improper classification and those resulting from reorganization.

Chairman Robert N.C. Nix (D-Pa.) has been assured by the president that the White House backs the plan, and will lobby for it. The measure has cleared the Appropriations Committee which had to act on it since it involves expenditures of money in cases where back pay would be ordered.

Nix ordinarily introduced legislation that would provide grandfathering protection to workers hit by demotions resulting from the discovery that their jobs had been improperly classified at too high a grade. The bill would not, of course, restore grades to workers who were demoted for cause.

Early in his administration, President Carter pledged that no federal workers would be fired, demoted or "hurt" because of reorganizations. That didn't protect the jobs of some workers at the CIA or Defense. But officials said they weren't bound by that promise since the firings and downgradings were the result of mission and program changes.

To make good on the nobody-gets-hurt promise, White House officials agreed to language that would extend the demotion protection to workers hit by reorganizations.

When agencies are reorganized, less senior employes often are hit by RIF's (reduction in force) and some senior workers get demoted and, using their "bumping" rights, they can displace other employes as they find other jobs.

The White House has again pledged to support the no-fault demotion bill, which carries Nix's name and his clout as chairman of the committee that will write it and manage it on the floor of the House.

Nix faces a tough Democratic primary fight in Philadelphia May 16. He's expected to win it, although some local politicians believe the race is too close to call.

Nix, one of only two black committee chairmen in the house, is getting support from federal employe unions both from Washington headquarters and in Philadelphia. Major Travis, top American Federation of Government Employes leader in Philadelphia, is working hard for Nix and believes the federal employe vote there could be the deciding factor.

But win or lose, Nix aides believe that he will push hard for the no-fault demotion bill, and that his committee will begin the markup process around May 22 or 23.

With administration support, the bill should clear the House easily.

Bottled Rats: Fedeal workers in a major department claim to have trapped dozens of rats, mice and other pests in their building. They've put them in bottles of alcohol to be used as exhibits unless the problems is cleared up soon.

An employe offered to show them to us the other day, but later said departmental officials had locked up the evidence. Since we haven't seen the evidence, we won't name the agency at this point.