Workers need more clarity from the prime minister on her pledge to protect workers’ rights after the UK leaves the European Union, the TUC has said.

The union call came after Theresa May said the UK “cannot possibly” remain within the European single market. In a 17 January speech, the prime minister also announced parliament would get a vote on the final deal agreed between the UK and the European Union. Addressing an audience including senior ministers and foreign ambassadors in central London, she said “a fairer Britain is a country that protects and enhances the rights people have at work. That is why, as we translate the body of European law into our domestic regulations, we will ensure that workers’ rights are fully protected and maintained.” She reiterated a previous commitment that “under my leadership, not only will the government protect the rights of workers set out in European legislation, we will build on them.”

Responding to the speech, TUC general secretary Frances O’Grady said: “We are pleased the prime minister has committed to a parliamentary vote on the final deal. But before that vote, we will need to know exactly what the new framework she promised for workers’ rights and jobs will be.” She added: “Working people are worried they will end up paying the price of leaving the Single Market. There is real concern that it will be bad for jobs, bad for rights at work, and bad for the living standards of British people. The commitment to protect workers’ existing rights and to build on them is welcome. The best way to do this is for the prime minister to agree that UK workers’ rights will always be as good as, or better, than workers’ rights in the rest of the EU.”