The union organisation said fewer visits were being made to workplaces by health and safety inspectors to make sure staff were not being put at risk.
The UK's safety record appears to be getting worse amid a "hostile" political climate to health and safety issues, the TUC has warned.
Local authority safety inspection teams are also working with "substantially reduced" funding, despite an increased in workplace deaths, said the TUC.
A report said the upward trend in workplace fatalities will be not be reversed unless there is an increase in the enforcement of health and safety law in all workplaces.
TUC general secretary Frances O'Grady said: "The Government seems determined to water down health and safety laws despite recent increases in workplace fatalities.
"It seems incredible that ministers seem unconcerned by the cut in the number of workplace inspections at a time when more people are dying and getting injured at work."