Plans for a major EU-US trade deal have been denounced by trade unions on the last day of their annual conference.
Delegates unanimously backed a motion opposing the Transatlantic Trade and Investment partnership (TTIP) and calling for negotiations to be halted.
Some trade unions and NGOs say that the agreement will threaten the future of the NHS and other public services.
The government insists it could boost the economy and open up the US market to British firms.
In recent months, unions have stepped up their opposition to the plan.
Many have focused on the potential impact on the NHS, where private firms are able to provide services.
They claim that TTIP would allow those firms to sue the government if it chose to return those services to public ownership.
Speaking at the conference, Gail Cartmail, assistant general secretary of the Unite union, called for the NHS to be protected from TTIP.
"Shame on this government because they have privatised our healthcare with no mandate," she said. "But they will not be allowed to sell-off our health service to America."
"If health is protected, why is it in there? Take it out," she said.
Simon Renton, president of the University and College Union, said that TTIP was also a threat to post-school education, as "profit-driven providers" had also entered the further and higher education sectors.