The U.S. Senate debating a trade bill Wednesday backed a plan that would limit retaliation against countries accused of violating labor and environmental standards.

Senators are debating a bill that would renew the president's authority to negotiate trade deals an authority that expired in 1994.

Under so-called 'fast track' authority, Congress votes for or against a trade deal negotiated by the White House, but cannot change the agreement. The Republican-led House passed the measure last year. But Democrats who control the Senate are seeking guarantees that future trade deals will include worker and environmental protections.

Senate Finance Committee Chairman Max Baucus, a Democrat from Montana, said the proposal he drafted with Republican Senator Charles Grassley of Iowa, does more to deal with labor and environmental issues than any previous trade bill.

His proposal was left intact after the Senate voted (54 to 44) to scuttle an amendment by Democratic Senator Joe Lieberman of Connecticut that would have allowed sanctions to enforce labor and environmental provisions in trade deals.

An opponent of the amendment, Republican Senator Phil Gramm of Texas, said the issue is critical to U.S. sovereignty. He argued international tribunals should not be allowed to decide claims filed by foreign nations or companies against U.S. labor or environmental laws. "This is not an environmental question, it is not a labor question, it is a sovereignty question," he said.

The amendment's defeat is a victory for the White House. The move comes a day after the administration lost a key vote when Senators passed an amendment giving themselves the power to vote on provisions in trade deals that they believe undermine existing U.S. laws.

The Bush administration says that amendment would hurt its ability to negotiate trade deals. It hopes to kill the provision when House and Senate negotiators work out differences in the two versions of the legislation.

White House spokesman Ari Fleisher said, "I think that the Congressional leaders have a very good understanding that that's a provision that needs to be removed at conference in order to get this agreed to. The president views that provision as a real show stopper, an anti-trade provision that can harm the cause of free trade, not help the cause of free trade. The president urges all members of Congress to resist the siren call of protectionism."

In other action Wednesday, Senators voted (65-33) for an amendment that calls on U.S. negotiators to decrease U.S. textile and apparel tariffs only if other countries reduce their own tariffs to the same level.

Democratic Senator John Edwards of the textile-producing state of North Carolina is a sponsor. "We need to make sure we do not leave behind millions of our fellow citizens who have been hurt by trade and trade policies," he said.

The amendment also encourages U.S. negotiators to consider whether foreign countries have lived up to earlier textile trade commitments before agreeing to a new deal.