Attempts to add an anti-abortion amendment to a bill protecting the job rights of pregnant women may reopen the abortion controversy in Congress and imperil the bill.

At least one liberal Democrat on the House Education and Labor subcommittee that is scheduled to mark up the pregnancy job rights bill on Thursday said he would vote against the bill if an anti-abortion amendment were adopted.

Rep. Ted Weiss (D-N.Y.) said, "The very purpose of the bill is to eliminate discrimination against pregnant women. I don't want to eliminate one kind of discrimination while at the same time replacing it with another. If I have to choose between two kinds of discrimination, I will try to defeat the bill."

Women's groups and civil rights groups have been working hard to keep the abortion amendment out of the bill. Last year, a controversy over an abortion amendment tied up an appropriations measure for the Departments of Labor and Health, Education and Welfare for months.

Though the details of the amendment are not clear yet, generally it would permit employers to withold pregnancy benefits from workers whose pregnancy ended in abortion.

Puerto Rican resident commissioner Baltasar Corrada, a subcommittee member, has been planning to offer an anti-abortion amendment, but he said yesterday he would not attend Thursday's mark-up session. He said he would attend the White House Conference on Balanced Growth instead.

Corrada said he was reserving the right to offer the amendment when the bill comes after the full committee. He said that though the courts have upheld a woman's right to an abortion, he does not believe that either the public sector or the private sector should have to pau for it.

The amendment may still be offered in the subcommittee perhaps by Rep. Albert H. Quie (R-Minn.). Quie said he would decide today whether to offer the amendment. "I feel it should be offered," he said.

Right-to-life groups and the U.S. Catholic Conference have been lobbying for the amendment. However, the Right-to-Life groups are not unanimous in their support. Some testified before the subcommittee that they fell the bill itself works to prevent abortions by assuring women that they will retain their jobs and job benefits after bearing children.

Sources said an anti-abortion amendment probably would be adopted both in the subcommittee and the full committee. The House has consistently supported strong anti-abortion language. The Senate passed the pregnancy job rights bill without anti-abortion language attached.