Richard Trumka, president of the American Federation of Labor & Congress of Industrial Organizations (AFL-CIO), speaks during a No Vote Until NAFTA 2.0 Is Fixed news conference in Washington, D.C., U.S., on Tuesday, June 25, 2019.Andrew Harrer | Bloomberg | Getty ImagesA top labor leader has cast doubts on the House quickly approving President Donald Trump’s replacement for the North American Free Trade Agreement.In an interview with The Washington Post published Wednesday, AFL-CIO President Richard Trumka said it would be a “colossal mistake” for the Democratic-held chamber to vote on ratifying the United States-Mexico-Canada Agreement soon. The head of the key labor group, which represents more than 12 million active and retired members across a range of industries, added that the agreement “would be defeated” if the House voted before Thanksgiving.Trumka’s comments underscore the sustained resistance to USMCA from labor groups even as the White House and key business organizations push for the deal’s swift approval. House Speaker Nancy Pelosi and top Democratic negotiators have said they want to resolve concerns about the deal harming American workers or the environment before they ratify it.The labor leader’s remarks undermine a key claim from the president as he makes his case for the deal: that major labor unions back USMCA.Spokespeople for Pelosi and the White House did not immediately respond to requests to comment on Trumka’s remarks.Trump sees USMCA ratification as a top political and economic priority ahead of the 2020 election. During his 2016 campaign, the president promised to overhaul U.S. trade relationships to stop companies from moving manufacturing jobs out of the country. Last month, White House trade advisor Peter Navarro said he saw a “100%” chance the House approved USMCA by the end of the year.Companies reliant on trade with America’s northern and southern neighbors have also pushed for approval of the deal. Myron Brilliant, executive vice president of the influential U.S. Chamber of Commerce, told Bloomberg last month that “we’re hopeful [USMCA] will be passed later this fall, I think before Thanksgiving.”Canada was the largest export market for American goods last year, followed by Mexico.Last week, Pelosi told reporters that Democrats are “on a path to yes” on the trade deal. She added that her caucus has not yet had its concerns about enforcing the agreement assuaged.They worry USMCA will not go far enough to stop companies from moving to Mexico in order to hire workers for lower wages than in the U.S.”We want to be sure that as we go forward, we are strengthening America’s working families and our farmers who are very affected by this,” she said.Read the full Post report here.Subscribe to CNBC on YouTube.