Reagan administration officials will have to fight most House Democrats and some Senate Republicans to win the right to overhaul federal pay, promotion and firing rules this fall.

Judging from what happened to the reform package last week, it could be a long summer for the White House.

President Reagan has personally endorsed a set of pending rules changes that would require employes to meet new job performance standards to qualify for within-grade pay raises and so-called career ladder (fast-track) promotions. Most employes (99 percent) now get the 3 percent pay raises every time they come due for them, which is every one to three years.

The new emphasis on performance would also revamp the rules that govern layoffs (reductions in force). Since the administration took office, about 2,900 workers here were fired for economy reasons. Most of those workers had little or no seniority.

The Office of Personnel Management, which proposed the rules change, says this is an internal matter to be handled administratively. But Congress--thanks to heavy lobbying from federal unions--is seeking to get into the act so it can modify or kill the proposed changes.

House Democrats oppose the reform package because they think it is a GOP plot to politicize the career civil service, and also just because Reagan proposed it. Most of them, however, approved the civil service reform act--which laid the groundwork for many of the new proposals--when their president, Jimmy Carter, (presumably of purer heart), made many of the same arguments for reform that Reagan is making now.

Sen. Ted Stevens (R-Alaska) says he will not allow the rules changes to be made without congressional approval. Alaska has a lot of government workers who, thanks to Stevens' influence, get a 25 percent, tax-free cost-of-living differential to cope with the state's higher prices.

Democrats in the House are working to block the reforms both this fiscal year (which ends Sept. 30) and in the fiscal year that starts this October.

Two weeks ago the Treasury-Postal Service-General Government Appropriations subcommittee voted a supplemental money package that would ban any reform action this fiscal year.

Last Thursday the subcommittee, working on next year's appropriations, voted to extend the ban through at least September of next year.

Taking another route, the National Treasury Employees Union last week asked the U.S. District Court here to order OPM to delay implementing the rules. The group said OPM failed to post the proposed regulations in federal agencies. It says the rules change cannot be made until OPM has posted them for 60 days.

If OPM can be kept from putting the rules into effect on its own, chances are that Congress will study them to death