A California congressman at the center of a legal battle with the White House ... asked U.S. trade officials to let him sit in on negotiations in San Diego next week between the United States and other countries in the Asia-Pacific region. Given the immense impact that this agreement will have on many areas of the American economy, including intellectual property, I respectfully request that you allow me and certain members of my staff to be present as observers for this round of negotiations," Republican lawmaker Darrell Issa said in a letter to U.S. Trade Representative Ron Kirk. The unusual request to join the San Diego talks on the proposed Trans-Pacific Partnership (TPP) pact, and a separate letter on Wednesday from about 130 congressional Democrats, reflect the anxiety many lawmakers are feeling about trade agreements, even though Congress last year overwhelmingly approved three such pacts -- with South Korea, Colombia and Panama. The roughly 130 Democratic lawmakers, in their letter, urged U.S. Trade Representative Ron Kirk to release draft texts under negotiation and "to engage in broader and deeper consultations" with members of Congress on U.S. laws and regulations they said he could be affected by the pact. Those include areas such as labor, patent and copyright, land use, food, agriculture, natural resources, the environment, state-owned enterprises, government procurement and regulations for financial services, healthcare, energy and telecommunications, the lawmakers said.