Wendell E. Primus, a deputy assistant secretary at the Department of Health and Human Services, has resigned in protest of President Clinton's decision to sign the welfare legislation approved by Congress Aug. 1.

Primus, who has been an influential figure at HHS and on Capitol Hill for years, said in his letter of resignation: "I believe strongly that a political appointee must be able to support the Administration's policies that fall under his purview. Given the President's decision to sign the welfare reform bill, I have no choice but to resign. To remain would be to disown all the analysis my office has produced regarding the impact of the bill."

The letter, dated Aug. 17, was sent to HHS Secretary Donna E. Shalala. Department officials said they would not comment on the resignation, and Primus declined to comment beyond his letter of resignation.

Primus, who was deputy assistant secretary in the department's office of planning and evaluation, was involved in a controversial analysis in the welfare debate last year, when HHS produced a study estimating the number of children that would be pushed into poverty if the bill before Congress were enacted.

Shalala took that analysis to the president to argue he should not support the bill, which he eventually vetoed twice.

The legislation approved this year, which Clinton has promised to sign, was changed substantially from the version last year. But an analysis released by the Urban Institute estimated the new bill would send 1.1 million more children into poverty. The institute estimated last year's bill would have increased the number of children in poverty by 1.5 million.

Before joining the administration in 1993, Primus was a longtime aide on Capitol Hill, heading the staff of the human resources subcommittee of the powerful Ways and Means Committee when the Democrats controlled the House. An economist, he played a central role in crafting earlier versions of welfare legislation.

The new legislation, which may be signed by the president within the next week or two, ends the 60-year-old federal guarantee of aid to any eligible, poor American. It turns over to the states control of Aid to Families With Dependent Children, replacing the open-ended stream of federal funds with an annual lump-sum payment to the states.

The law requires adults on welfare to work and limits benefits to five years. It also ends many forms of aid to most legal immigrants and restricts future spending on food stamps.

The question of whether Clinton should sign this bill was bitterly debated within the administration. Some aides argued that the legislation was much improved since it was initially introduced and that it would hurt the president politically to veto it for a third time.

Others contended the measure was still too harsh, particularly on immigrants. Clinton, in announcing his support for the bill, criticized its provisions on immigrants and food stamps and vowed to revisit them in new legislation.