Since 1964, when Congress passed landmark civil rights legislation, our nation has made tremendous progress toward equal opportunity. Today, however, Congress is on the threshold of passing legislation that takes an altogether different approach from the 1964 act. Contrary to the views expressed by Rep. Augustus Hawkins (D-Calif.) {op-ed, Sept. 18} and The Post {editorial, Oct. 2}, the Civil Rights Act of 1990 (the Kennedy-Hawkins bill) would replace the historic 1964 law with a statute that would pressure many employers to adopt secret quotas to avoid lawsuits that are rigged against them.

The quota problem is created mainly, though not exclusively, by the bill's treatment of the Supreme Court's 1989 Wards Cove decision and the ''business necessity'' rule that has been developed by the courts. The issue arises in ''disparate impact'' cases when a plaintiff alleges that a particular hiring or promotion practice unintentionally caused a statistical imbalance in the racial or sexual composition of an employer's work force. If a plaintiff shows that such an imbalance has resulted, the employer can defend the practice by arguing that it is justified by legitimate business objectives.

The issues raised by the Wards Cove decision are which party bears the ultimate burden of proof on that question and what is the scope of the burden. The Wards Cove decision resolved those issues by placing the burden of proof on the plaintiff and defining the burden as ''significantly'' serving a ''legitimate'' business interest.

Changing the law to shift the burden to the employer has long been acceptable to the administration and to a broad congressional coalition led by Sen. Nancy Kassebaum (R-Kan.) and Rep. John LaFalce (D-N.Y.). Unfortunately, despite this and many other compromises offered during months of negotiations, proponents of the pending bill have unbendingly demanded a complete rewrite of disparate impact jurisprudence.

First, their bill permits plaintiffs to establish a legal violation on the basis of statistical disparities alone, without identifying the specific practice that caused the disparities. This approach is unacceptable because it removes the fundamental obligation of all civil plaintiffs to identify what act of the defendant is allegedly responsible for the plaintiff's injury. Moreover, some disparities are not caused by the employer's practice. Even when none of an employer's practices causes a disparate impact on minorities or women, under the bill overall ''bad'' numbers could force the employer to prove that every single practice either meets the "business necessity" test or has no statistical effect. This is unprecedented in our statutes and wrong.

Second, their bill creates a brand-new ''business necessity'' test that would make it extremely difficult to defend sound and legitimate business practices. For instance, employers could be required to defend, under unreasonably strict standards, the decision not to hire convicted felons.

Proponents of the Kennedy-Hawkins bill contend that it has been amended to say that it does not ''require'' quotas. But while the bill does not use the word ''quotas,'' it makes them irresistible to those employers who need to avoid costly litigation in order to stay in business.

The Post editorial makes the erroneous assumption that the Kennedy-Hawkins bill would not create quotas because it simply restores the law of Griggs. That is simply not true. Kennnedy-Hawkins imposes a legal standard that has never been the law of the land. Indeed, if it were simply a matter of restoring Griggs there would be no debate. On the important issue of what constitutes "business necessity," the administration has proposed the definition that was adopted in Griggs, but the sponsors of Kennedy-Hawkins rejected it.

And it is not an answer to argue, as The Post does, that quotas did not occur before and likely will not occur in the future. The bill is not restorative, and in any event, no company would admit to using surreptitious quotas, because such quotas are illegal under the 1964 act. The fact is that plain common sense would drive employers to use quotas.

Nor is it an answer to argue, as The Post does, that the quota problem has been solved by compromise language dealing with business practices. The bill's definition of "business necessity" is also stacked against employers and does not encompass the many legitimate employment practices unrelated to job performance that are properly considered in hiring.

Whatever smoke screens are thrown up by advocates of the bill, those who must live under it would have to deal with what it actually says. Employers whose numbers are ''off'' would face the prospect of lengthy, expensive and potentially polarizing lawsuits under rules that virtually guarantee that they will lose in court. The use of surreptitious quotas would insulate them from such litigation, and at far less expense and disruption to their businesses.

President Bush has made clear his commitment to civil rights and to signing a genuine civil rights bill. This past July he signed the Americans With Disabilities Act, landmark legislation protecting the civil rights of people with disabilities. The disabilities act was carefully and deliberately prepared and debated. The same care has not been taken with this bill.

Even so, the administration has offered to accommodate every reasonable concern articulated by proponents of the Kennedy-Hawkins bill -- shifting the burden of proof, making additional adjustments in the rules of disparate impact and creating new remedies for work-place harassment. None of this has been enough for those who are seeking to rewrite -- under the guise of ''restoring'' -- a law that has worked very well for a quarter of a century.

The writer is assistant attorney general in charge of the civil rights division of the U.S. Department of Justice.