WASHINGTON — More than half of the House Congressional delegation from New York State came out against the 12-nation Trans-Pacific Partnership pact on Wednesday, creating a new hurdle for the trade deal at a time when the Obama administration is trying to garner votes to ratify it on Capitol Hill.

Nineteen Republican and Democratic House lawmakers sent a letter to President Obama expressing their “firm opposition” to TPP. The delegation has 27 members, with 18 Democrats and nine Republicans.

“New York State is home to the best workers and some of the most innovative companies in the world. As bipartisan Congressional representatives of the people and businesses of New York, we write to express our firm opposition to the Trans-Pacific Partnership as negotiated,” they wrote in the letter.

The bipartisan group, led by Republican Reps. Chris Collins and Democrat Louise Slaughter, also includes Reps. Carolyn Maloney and Jerrold Nadler, both Democrats and chairs of the “Congressional Apparel Manufacturing and Fashion Business Caucus” that they helped launch in 2010 to represent the interests of the New York City garment center.

“Western New York bears the scars of poorly negotiated past free-trade agreements — scars like lost jobs, shuttered factories and a generation lost to economic opportunities that were outsourced to foreign competitors,” said Collins. “I cannot support a trade agreement that once again threatens America’s working middle class, and fails to address several of the biggest challenges facing American manufacturers, including currency manipulation and intellectual property protection.”

Trade ministers signed TPP in early February. It includes the U.S., Australia, Japan, Mexico, Canada, Vietnam, Malaysia, Peru, Singapore, Chile, Brunei and New Zealand and aims to remove barriers to trade to encompass nearly 40 percent of the world’s gross domestic product if enacted.

The sweeping trade deal is a cornerstone of Obama’s trade agenda and could be a key component of his legacy. But the controversial pact has run into opposition among key Republican leaders on Capitol Hill, as well as most of the presidential candidates on the campaign trail.

Obama has gained support for TPP from major business groups and is working to build broader support in Congress. But the opposition from such a large contingent of New York lawmakers adds to the challenges the Obama administration is facing to get the deal across the finish line.

“Like many Americans, New Yorkers have grown increasingly disillusioned with our nation’s international trading relationships and are rightly skeptical that the TPP will fare better than previous trade agreements,” the lawmakers said in the letter to Obama. “In the months since the TPP’s text was released to the public, we have made a careful review of its wide-ranging provisions. Our concerns with the TPP are as varied as the people and districts we represent, but there are a number of core issues with the agreement that we all share.”

New York has lost 370,000 manufacturing jobs, while the country as a whole has lost an estimated 5 million manufacturing jobs since the North American Free Trade Agreement with Mexico and Canada went into effect in 1994, according to the bipartisan group.

They added that while it is difficult to make a causal connection between trade deals and job losses, the federal government has certified more than 115,000 people in New York jobs to qualify for the Trade Adjustment Assistance program, which provides assistance to workers whose jobs are displaced by imports, in the same time frame.

They argued that the jobs certified under TAA represents “only a fraction” of New York job losses attributable to trade deals.

“Glaringly, this TPP agreement has no effective measures to address currency manipulation,” they said. “Currency manipulation is one of the greatest issues facing American manufacturers today and is estimated to have suppressed millions of U.S. jobs.”

Japan, Malaysia and Singapore have “histories of artificially controlling their currencies, yet the TPP provides no enforceable protections against their doing so,” they said.

The lawmakers also criticized a side declaration on currency practices negotiated by the 12 countries as “insignificant, unenforceable, and does little to assuage our concerns.”

“The TPP is the United States’ best chance to address currency manipulation in a systematic way, and the lack of meaningful currency provisions makes the TPP incomplete at best and destructive to domestic manufacturers at worst,” they added. “Given a level playing field, New York workers and businesses can compete and win in the global marketplace. While we each have our own concerns with the Trans-Pacific Partnership, we are united in our opposition to the agreement and in our belief that the TPP will harm many working and middle-class families in New York and across the country.”