Two-thirds of House Democrats on Wednesday wrote to the White House's top trade official complaining they are being left out of the loop as the Obama administration negotiates the most consequential trade deal in decades, the Trans-Pacific Partnership Free Trade Agreement.

The 132 Democrats, led by Reps. George Miller of California and Rosa DeLauro of Connecticut, urged U.S. Trade Representative Ron Kirk to make sure "there is ample opportunity for Congress to have input on critical policies that will have broad ramifications for years to come."

Also this week, the Republican chairman of the House Oversight Committee, Rep. Darrell Issa of California, asked Kirk to allow him to attend the next round of TPP negotiations in San Diego next month, saying that would "help to alleviate some of my concerns about the process through which the agreement is being negotiated."

The United States and eight other Pacific nations — Australia, Brunei, Chile, Malaysia, New Zealand, Peru, Singapore and Vietnam — have been negotiating some three years on the agreement that would lower trade barriers and spur economic growth in the region. Mexico and Canada are set to join in the 13th round of negotiations in San Diego and Japan has expressed interest in future participation.

The House Democrats, who in the past have tended to be skeptical of free trade accords, expressed concern that the trade deal could force on the United States binding policies related to labor, food standards, the environment, patents, and financial, healthcare, energy and telecommunications regulations. "We are troubled that important policy decisions are being made without full input from Congress."

The USTR, in a statement on its Web page, said that while the U.S. and its Trans-Pacific partners had entered into a customary confidentiality arrangement on private talks, "USTR consults extensively with key congressional committees, interested members of Congress, as well as a wide range of trade advisory committees."

USTR spokeswoman Carol Guthrie said the agency "will be continuing our already unprecedented outreach to keep the public more informed about TPP" while ensuring its ability to conclude successful negotiations. She said they would discuss the issue further with the House Democrats and were working with Issa's office on his request.

In May, Sen. Ron Wyden, D-Ore., head of the Senate Finance subcommittee on international trade, introduced legislation that would give all members of Congress and staff with appropriate clearance access to the substance of trade negotiations.

The Trans-Pacific agreement, he said in introducing the bill, could be the most far-reaching economic agreement since the World Trade Organization was established nearly 20 years ago. But "the majority of Congress is being kept in the dark as to the substance of the Trans-Pacific negotiations, while representatives of U.S. corporations — like Halliburton, Chevron, PHRMA, Comcast and the Motion Picture Association of America — are being consulted and made privy to details."