Future survivors of federal workers and retirees would lose much of their benefit protection under the budget approved last week by the Senate.

None of the nearly 500,000 people already drawing survivor benefits would be affected by the proposed change.

Under current law, all widows and widowers of federal personnel are entitled to survivor benefits equal to about 20 percent of their spouses' salaries.

Under the Senate plan, which must still be approved by the Governmental Affairs Committee, the House and the White House, the civil service survivor program would be changed to conform to social security practices.

That would mean benefits could only be paid to:

* Widows and widowers who had children under the age of 17.

* Disabled survivors who are over the age of 49. All survivors over the age of 59.

* Children up to age 19 who remain in school.

At present they get benefits until age 22 if in school.

The budget approved by the Senate last week is part of a three-year deficit reduction package that recommends cuts in programs ranging from defense and social security to civil service.

The exact nature of the cuts would be left to the committees of jurisdiction.

In civil service matters, the oversight panel is the Governmental Affairs Committee.

The House is expected to approve its budget next month.

Proposed federal pay and pension changes will be reviewed by the Post Office-Civil Service Committee.

The Senate budget would skip pay raises due federal employes in January and cost-of-living adjustments due retired government workers and military personnel.

Employe contributions to the civil service retirement fund would be raised from 7 percent to 9 percent of salary in January 1987.