The concern is that eliminating barriers to trade and investments will undermine collective bargaining agreements and shift production to areas where labor is cheapest.

But trade expert Daniel Ikenson at the Cato Institute says that should not be an issue for the U.S.

"In fact, Europe's labor standards are widely considered to be higher than ours so the U.S. labor movement would be less likely to oppose the agreement," Ikenson said.

Instead, he says negotiations could focus on harmonizing technical and regulatory standards.

"If you produce something in the United States for example -- a washing machine -- the electrical cord needs to be three feet and in the European Union, it needs to be one meter, which is three feet and three inches," Ikenson said.

Given that trade tariffs are already low between the U.S. and Europe, major hurdles are likely to revolve around subsidies -- the financial aid governments give such groups as farm producers and aircraft manufacturers to stay competitive.

But even if both sides are able to work out their differences, labor leader Sharan Burrow says more trade is not the cure for a weak global economy.

"This economy is never going to get back on track in the global context unless we can do something about stopping the attack on worker's rights -- giving the world a pay raise so people can build a capacity to live on what they earn and stabilize demand," Burrow said.