There's a new twist to the battle over the proposed U.S.-Dominican Republic-Central American Free Trade Agreement known as CAFTA.

The AFL-CIO labor group and International Brotherhood of Teamsters have filed a petition with the U.S. Trade Representative to remove El Salvador from the list of developing countries eligible for U.S. trade benefits, charging a "pattern of denying internationally recognized worker rights."

The petition charges El Salvador fails to enforce labor laws and rules that protect the rights of workers to unionize.

A U.S. government decision in favor of the unions would disqualify El Salvador from CAFTA and other U.S. trade benefit programs.

El Salvador's parliament approved CAFTA on Dec. 17, becoming the first legislature of the seven participating nations to do so.

The AFL-CIO and Teamsters reject CAFTA, charging the pact will hasten the "race to bottom" and the flight of U.S. jobs to lower-wage countries with weaker labor standards.

The Bush administration plans to present CAFTA to Congress for approval this year.