Free trade has never been free for the American worker.

That’s how it looks to Mike Basso, who works as a field technician for Verizon in New York City.

Basso’s union, the Communications Workers of America, is part of a broad coalition of labor, environmental, consumer-rights, good-government and other groups fighting against a proposed new trade deal, the Trans-Pacific Partnership, which is being promoted by President Barack Obama and is now before Congress.

Basso says the proposed pact would take jobs from New Yorkers as companies such as Verizon outsource more work to lower-wage countries.

“Tech support jobs, customer service jobs, operator jobs — those are the jobs they’re sending overseas,” said Basso, a union steward for his local.

Recent history proves his point: Following the passage of the North American Free Trade Agreement, Verizon alone outsourced about 1,000 jobs, he said.

And the Trans-Pacific Partnership will have even further-reaching consequences, he said: It is “NAFTA on steroids.”

TPP, as the proposed deal is called, would set new terms for trade and business investment among the 12 countries on the Pacific Rim, including the United States, Australia, Japan, Vietnam and Malaysia. Together these countries account for 40 percent of the world’s total gross domestic product and one-third of all trade.

Supporters including Obama say TPP would boost the economies of all countries involved.

Critics counter that recent trade deals have hurt the U.S. middle class.

In the early 1990s, President Bill Clinton promised that NAFTA would create 200,000 jobs in two years. But NAFTA’s real legacy is lost jobs and stagnant wages, economist Robert E. Scott wrote in an online article for the Economic Policy Institute.

“NAFTA led to a flood of outsourcing and foreign direct investment in Mexico,” Scott wrote. “Jobs making cars, electronics, and apparel and other goods moved to Mexico,” and as a result NAFTA cost the United States 682,900 good jobs.

Trade agreements since, such as those with China and South Korea, have similarly led to the movement of jobs offshore and disinvestment in the United States, critics say.

With TPP, one concern just as great as potential job loss is the power that the pact would give to multinational corporations to challenge any national or state statutes — such as rules regulating pollution — based on the claim that they hinder “free trade.”

As New York State Attorney General Eric Schneiderman wrote in Politico, “The separate and unaccountable system of justice that TPP would create poses a major risk to critical statutes and policy decisions that protect our citizens — and it has no place in a nation committed to equal justice under the law.”

Also troubling to critics is that the Obama administration has kept the details of the trade deal secret from the public and is pursuing fast-track authority that would force Congress to take a straight up-or-down vote on the pact, with no ability to make amendments.

If TPP is passed, public school educators will see the impact of the lost jobs in their communities and schools, said Nina Tribble and Bobby Greenberg, who co-chair the UFT’s Committee on Social and Economic Justice.

“TPP will affect millions of workers negatively and that means millions of our kids’ parents and the communities in which they live and we teach,” Greenberg said.