"If these rulings prevail, they could wreak havoc with policies designed to curb performance-enhancing drug use in professional sports," Rep. Henry Waxman, the chairman of the House Energy and Commerce Committee, said at a subcommittee hearing. "In fact, if the rulings are taken to their logical conclusion, players on one team could be allowed to use drugs that would subject players on another team to suspensions and fines."

"In short," he added, "these new legal interpretations could render the NFL and Major League Baseball drug testing programs unenforceable, loophole-ridden, and unacceptably weak and ineffective."

Waxman, a California Democrat who has held high-profile hearings on steroids in sports, said that if the court rulings are not reversed, "then we need to find out if the collective bargaining process can solve these problems or whether congressional action is needed.

"One thing is clear: we should not allow the drug policies that the NFL, Major League Baseball, and other sports leagues have put in place to be rendered null and void. That is an invitation to steroid abuse in professional sports. And it will inevitably lead to more steroid use on high school football fields and baseball diamonds."

NFL commissioner Roger Goodell was to testify later and planned to ask for legislation.

"We believe that a specific and tailored amendment to the Labor Management Relations Act is appropriate and necessary to protect collectively bargained steroid policies from attack under state law," Goodell said in his written testimony.

Recent court decisions "call into question the continued viability of the steroid policies of the NFL and other national sports organizations," Goodell said.

The NFL had attempted to suspend Minnesota Vikings Pat Williams and Kevin Williams for four games, but the players sued the league in state court, arguing the league's testing violated Minnesota laws. The case was moved to federal court, and the NFL players union filed a similar lawsuit on behalf of the Williamses and New Orleans Saints players who were also suspended.

In May, a federal judge dismissed the union's lawsuit and several claims in the Williamses' case but sent two claims involving Minnesota workplace laws back to state court. A judge there issued an injunction prohibiting the NFL from suspending the players and has scheduled the trial for March 8. In September, a federal appeals court panel agreed with those decisions, essentially allowing the Williamses, who are not related, to continue playing while the case proceeds in state court.

The Vikings players tested positive in 2008 for the diuretic bumetanide, which is banned by the NFL because it can mask the presence of steroids. The players acknowledged taking the over-the-counter weight loss supplement StarCaps, which did not state on the label that it contained bumetanide. Neither player is accused of taking steroids.

The court ruling led the NFL to allow New Orleans defensive ends Charles Grant and Will Smith, who had also been issued four-game suspensions, to continue playing. Both players also tested positive for bumetanide.

DeMaurice Smith, executive director of the NFL players union, said this case differs from others. He said Dr. John Lombardo, who oversees the league's steroid policy, learned that StarCaps contained bumetanide but did not inform the players.

"Frankly, the fundamental failure of that doctor to ensure immediate disclosure of the fact that StarCaps included bumetanide violated his paramount duty as a doctor _ to protect patients, in this case, our players," Smith said in his prepared testimony. Smith called for changes to the league-union steroid policy that would mandate the NFL notify players when it learns that a product contains a banned substance.

Rob Manfred, Major League Baseball's executive vice president of labor relations, also discussed a legislative remedy in his testimony. He said a "narrowly drafted statute could solve the problem faced by professional sports" while preserving the role of collective bargaining in drug programs without interfering with states' prerogatives.

But Michael Weiner, the union's general counsel, said that legislation is unnecessary. A bill to pre-empt state law, he argued, "would stand for the unusual proposition that parties to a collective bargaining agreement can contract for that which is illegal under state law."