WASHINGTON (AP) — A senior Democratic senator's complaints Tuesday, and noisy protesters, underscored the Obama administration's challenge in seeking congressional approval for enhanced powers to cut trade deals with Japan, Australia and many other countries.

Sen. Charles Schumer of New York said he worries that new trade deals will not help middle class incomes. He also insisted the United States do more to prevent China from keeping its currency's value artificially low, which enhances Chinese exports and dampens imports.

Schumer addressed his remarks to U.S. Trade Representative Michael Froman, who made the administration's pitch to Senate and House committees Tuesday.

Froman said Congress must return "trade promotion authority" to the White House in order to cut important trade deals with Pacific-rim nations and others. That power, sometimes called "fast-track" authority, allows presidents to send proposed trade agreements to Congress for yes or no votes, with no amendments.

Several Republican senators on the Finance Committee, including Rob Portman of Ohio, strongly backed the administration's push. Portman, who held Froman's job under President George W. Bush, said foreign markets are rapidly growing, and "our workers are getting left out." He said President Barack Obama is the first president since Franklin Roosevelt to lack enhanced trade negotiating powers, which Congress enacts from time to time, usually with bipartisan votes.

But many Democrats, liberals and labor unions have grown increasingly hostile to trade deals, saying they reduce U.S. jobs.

Several anti-trade protesters interrupted Froman's opening remarks, and were ushered out by police. Some mentioned the 1994 North American Free Trade Agreement, which many labor groups disdain.

The administration is pushing trade agreements on two tracks. Froman said his team is nearing completion of lengthy negotiations with Japan and 10 other Pacific-rim nations. But to enact that proposal — and any other major trade deal — a U.S. president must be able to send Congress a pact it can ratify or reject, but not amend, leaders of both parties say. That's why the White House's biggest goal — and its opponents' biggest target — is trade promotion authority, or TPA. It could clear the way for the Pacific-rim pact, and possibly others.

Anti-trade groups say new trade deals make it easier for foreign countries to take away U.S. jobs while abusing the environment, patent rights and, sometimes, local workers. Froman said his negotiating team is pushing India and other countries to include greater safeguards for workers and the environment as they seek new trade agreements.

China is not part of the pending Pacific-rim deal, but it figured heavily in Tuesday's debates.

Schumer said he won't support the Pacific-rim deal "if we do not at the same time enact new statutory law that includes objective criteria to define and enforce against currency manipulation" in China and elsewhere.

Froman said his team has made progress on the China currency issue, but needs to do more. He said he's pushing China on other issues too, "including protection and enforcement of trade secrets and other intellectual property rights."

Senate Finance Committee Chairman Orrin Hatch, a Utah Republican, urged his colleagues to approve trade promotion authority. "Simply put, trade means jobs," Hatch said, rejecting the opponents' claims about job losses.

Several lawmakers predict the Senate will support TPA, with overwhelming support from Republicans, plus a fair number of Democrats.

Prospects in the House are less certain. A big majority of House Democrats oppose new trade deals, and some Republicans appear increasingly dubious. That's especially true among tea party Republicans, whose politics lean toward populism.

Froman was scheduled to address the House Ways and Means Committee later Tuesday.