In the margins of talks for a Transatlantic Trade and Investment Partnership (TTIP) on Thursday (23 April), US opponents to the deal vocally criticised the emerging agreement, saying it was a bad deal for consumers and the environment.

Critics included Jean Halloran, a senior adviser at the nonprofit Consumers Union, who suggested that a treaty would be the worst of all possible worlds, exposing European consumers to “faulty GM cars” and US children to toys that do not meet strict American standards.

“We cannot pursue mutual recognition or equivalence willy-nilly,” she said. Halloran’s remarks came during a three-hour stakeholders meeting.

Negotiators are meeting this week (20-24 April) for the ninth round of talks on TTIP, and are determined to make progress on all strands of the deal, but particularly on regulatory cooperation.

>>Read: EU, US trade talks seek to advance regulatory pillar

The agreement, which could create the world’s biggest free-trade pact, has been billed by President Barack Obama and European Union leaders as critical to boosting economic growth and jobs in both regions.

Last week, Obama called for “major progress” on TTIP, saying the proposed major trade pact with Asia-Pacific countries would “absolutely” benefit American workers.

Supporters from across the business community emphasized on Thursday that standardizing rules could boost jobs in both regions.

But the talks have prompted large protests in Europe, where thousands rallied last weekend in Madrid and Brussels, and throughout Germany.

>> Read: Thousands across Europe protest against TTIP

Opponents in the US have yet to take to the streets en masse, but about half of the roughly 60 scheduled presenters appeared to be TTIP foes, based on the names of their organisations. Some of the speakers did not show up, including Frack Free Nation and the Open the Cages Alliance.

Other frequent subjects of criticism included the secrecy surrounding the closed-door talks, as well as a Investor-State Dispute Settlement (ISDS) mechanism that campaigners say would undermine national sovereignty and favor big business.

Sharon Anglin Treat, a representative of the National Caucus of Environmental Legislators, said the trade agreement could gut stricter rules enacted by states, such as laws in Massachusetts and New Jersey to label or restrict bee-killing pesticides.

“US state laws and regulations do diverge from US federal law and EU regulations,” Treat said. “That divergence is a hallmark of the US system of federalism and is enshrined in our Constitution.”

But Ann Wilson of the Motor and Equipment Manufacturers Association urged negotiators to advance the talks, which offer the chance of uniform standards across jurisdictions.

“We are a global industry,” she said. “It is important that we be able to operate on a global basis.”

Eugene Philhower, a representative of the US Soybean Export Council, said that American farmers are as concerned about animal welfare and sustainability as their counterparts in Europe.

“American producers are just as interested in animal welfare,” he said. “The biggest difference is whether to mandate it by the government.”

If concluded, TTIP would be the world’s biggest trade deal, linking about 60 percent of the world’s economic output in a colossal market of 850 million consumers, creating a free-trade corridor from Hawaii to Lithuania.