Unite accused ministers of introducing "light touch" health and safety regulations and called for an increase - not a decrease - in the number inspectors and workplace inspections.
The union said official statistics had enabled the Government to suggest UK health and safety is better than everywhere else but claimed this is a complete myth, since the real number of people killed in work-related incidents each year is probably closer to 1,400, over eight times the official Health and Safety Executive figure for 2011 of 171.
In addition, the union said 20,000 more women and men die every year - some estimates put this as high as 50,000 people - from occupational diseases, such as mesothellioma and cancers caused by negligent exposures at work to hazardous substances, such as asbestos, chemicals and dusts.
Unite's general secretary, Len McCluskey said: "The government is hell bent on reducing health and safety regulations, and standards. It will lead to fewer inspections, less enforcement and more deaths, injuries and ill-health at work.
"The Government strategy, built on myth and dogma, puts workers at greater risk.
"Unite has been very critical of the annual statistics on deaths at work, since these are only the tip of the iceberg, and represent a massive underestimate of the true problem.
The TUC has called for a day of action to defend health and safety.
Unite is calling for no reduction in the legal protection for workers on health and safety; those who create risk must be held accountable; no freedom from inspections and an increase in inspector numbers; recognition and support for the role that union safety representatives play; and more action to prevent occupational diseases.