Washington ? The U.S. Supreme Court is expected to rule Thursday on a potentially far-reaching challenge to Texas’ homosexual sodomy law.

The case, lodged by two gay men from Houston, is one of several awaiting decisions before the nine-member court goes into summer recess Thursday. But those rulings could be overshadowed if any of the justices choose the final day of the term to announce a retirement from the bench.

Chief Justice William H. Rehnquist, 78, Justice Sandra Day O’Connor, 73, and Justice John Paul Stevens, 83, are considered possible retirees from the court. All three have kept quiet about their intentions.

The court is being asked to strike down the 1973 Texas Homosexual Conduct Law, which prohibits sodomy among homosexuals but does not outlaw the same behavior for heterosexuals. Similar laws are on the books in Kansas, Oklahoma and Missouri. In addition, nine other states have laws outlawing sodomy for both heterosexuals and homosexuals.

The lawsuit is considered the most significant gay rights challenge in two decades and goes far beyond the single statute in Texas. A ruling in favor of the plaintiffs could topple the court’s 1986 decision that upheld a Georgia sodomy law. It would give gays and lesbians a stronger legal foundation to challenge other laws that they consider discriminatory.

Although the sodomy laws are enforced infrequently, Michael Adams, an attorney with Lambda Legal Defense and Education Fund, which represents the plaintiffs, said their existence resulted in other forms of discrimination against gays and lesbians. The laws have been cited as a basis for denying them jobs and preventing them from adopting children, he said.