By John S. McClenahen "Time is of the essence," in getting U.S. Senate approval of so-called trade promotion authority (TPA), claims the Washington, D.C.-based National Association of Manufacturers (NAM). "Ongoing negotiations in the World Trade Organization, the Free Trade Area of the Americas, and the Chile and Singapore bilateral negotiations must not be allowed to lose steam," says NAM. "Our competitors have accelerated their trade agreement negotiations, and we must do the same," the manufacturing group is telling U.S. Senate leaders Thomas Daschle, D-S.D., and Trent Lott, R-Miss. But the Democrat-controlled Senate differs on the details of a TPA measure that passed the Republican-controlled House of Representatives by one vote on Dec. 6, 2001. The Senate could take up TPA once it returns in April from its Easter recess. But there are suggestions that differences over employee trade adjustment assistance, labor standards and environmental protection issues could delay Senate consideration until mid-summer. TPA, which used to be called fast-track authority, would allow Congress to accept or reject -- but not amend -- trade deals the White House negotiates with other countries. Such presidential authority expired in 1994.