The U.S. Congress's fight over President Barack Obama's proposed Pacific Rim trade deal is sometimes a fog of abbreviations. Here is a guide to key proposals and programs involved. Trans-Pacific Partnership (TPP) The core of the fight is this proposed pact between 12 Pacific Rim trading partners, supported by Obama and Republican leaders and some Democrats. Meant to lower trade barriers and set common standards on issues ranging from workers' rights to intellectual property protections, the deal would cover the United States, Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam. Many Democrats and labor unions worry the trade deal, which is close to completion, would hurt U.S. jobs as companies take advantage of lower labor costs in partner countries and find themselves under increased pressure from duty-free imports. Trade Promotion Authoity (TPA) Also known as "fast-track," this measure, favored by Obama, would streamline passage of trade agreements through Congress. As proposed, TPA would set objectives for U.S. trade negotiators and a timeframe for making the text public. It would also require notification to Congress of proposed changes to laws. But TPA would limit lawmakers to casting only a "yes" or "no" vote on the TPP and other trade deals. They could not suggest amendments to it. The bill also would also set deadlines for congressional votes, limiting the potential for delays. Japan has said that TPA, which would give trading partners confidence that trade agreements would not be picked apart in Congress, is needed for TPP to proceed. Trade Adjustment Assistance (TAA) This is a federal program that gives aid to U.S. workers who lose their jobs as a result of foreign trade. They can get benefits such as relocation assistance, subsidized healthcare insurance, career counseling and income support while in job training programs. The program is set to expire on September 30. Democrats strongly favor TAA; Republicans generally do not. More than 2 million workers have qualified for benefits under TPA since 1974. The White House says nearly 77 percent of 2014 TAA participants found a job within six months of completing the program.