A bipartisan effort is under way in the House to prevent a federal retirement stampede next month if certain tax reform provisions become law.

Nearly 250,000 government workers -- one tenth of the federal work force -- are eligible to retire now. The tax reform bill approved by the House would eliminate a major retirement benefit for those veteran workers.

It allows them to draw tax-free pensions for a time until all contributions previously taxed as part of salary are recovered.

That tax-free period can last years, but on average, contributions are recovered within 18 months. Many feds count on the tax-free time when making financial plans for retirement.

The Senate Finance Committee's tax reform bill calls for a gradual change in the system, over a two-year period that would begin in January 1988. The Senate and House plans would both require new retirees to pay taxes immediately on a portion of their annuities. Taxable amounts would be based on life expectancy.

Federal personnel officials have warned that ending the tax benefit could push thousands of workers who want to beat the deadline into retirement -- all at the same time.

Although it could be months before Congress approves a final tax reform bill, it could choose to make the pension tax change retroactive to July 1. That is unlikely.

But to ward off the possibility -- and to keep thousands of federal workers from retiring in July just to be safe -- Ohio Democratic Reps. Tony P. Hall and Mary Rose Oakar and Virginia Republican Frank Wolf are asking the House to pledge in a resolution that there will be no retroactive pension tax change. Holidays Furloughs?

Agriculture's money-saving plan to furlough 9,000 employes on three holidays may be in trouble.

Rep. Michael D. Barnes (D-Md.), who co-chairs the civil service caucus, plans to make an announcement on the subject tomorrow, and is expected to produce a Government Accounting Office finding that the furlough plan is illegal.

Agriculture's Food and Safety Inspection Service came up with the idea to comply with budget cuts. The service announced that it would lay off staffers, including 850 here, on Memorial Day, Independence Day and Labor Day as a means of saving money without causing problems for meat and poultry processing plants. The plans can't operate without federal inspectors.

Many workers protested the holiday furlough idea, saying that if they must be furloughed it should be on a regular work day. Employe unions went to Congress and the courts seeking to block the furloughs.

The GAO finding Barnes is expected to release was made at the request of the Federal Government Service Task Force. Job Mart

The Energy Department needs a payroll clerk or payroll technician, Grade 4 through 6, to work in Germantown. Call Phyllis Settles at 252-9303. It also has downtown openings for a graphic assistant and a building operation assistant, GS 5. Call Gracie Reese at 252-8565.

Naval Research Lab is looking for guards, GS 3 through 5. Call Margaret Copeland at 767-3030.

Interior's Office of Surface Mining in Greentree, Pa., is looking for an administrator (senior executive service level). Call Essie Gross at 343-4153.