The US Supreme Court has blocked President Joe Biden’s rule requiring workers at large companies to be vaccinated or masked and tested weekly.
The justices at the nation’s highest court said the mandate exceeded the Biden administration’s authority.
Separately they ruled that a more limited vaccine mandate could stand for staff at government-funded healthcare facilities.
The administration said the mandates would help fight the pandemic.
President Biden, whose approval rating has been sagging, expressed disappointment with the decision “to block common-sense life-saving requirements for employees”.
He added: “I call on business leaders to immediately join those who have already stepped up – including one third of Fortune 100 companies – and institute vaccination requirements to protect their workers, customers, and communities.”
Former President Donald Trump cheered the court’s decision, and said vaccine mandates “would have further destroyed the economy”.
“We are proud of the Supreme Court for not backing down,” he said in a statement. “No mandates!”
The administration’s workplace vaccine mandate would have required workers to receive a Covid-19 shot, or be masked and tested weekly at their own expense.
It would have applied to workplaces with at least 100 employees and affected some 84 million workers. It was designed to be enforced by employers.
In a 6-3 decision, the justices agreed with that argument, saying that the workplace safety rule for large employers was too broad to fall under the authority of the Department of Labor’s Occupational Health and Safety Administration to regulate workplace safety.
“Covid-19 can and does spread at home, in schools, during sporting events, and everywhere else that people gather,” the court’s majority wrote.
“That kind of universal risk is no different from the day-to-day dangers that all face from crime, air pollution, or any number of communicable diseases.”
“This is no ‘everyday exercise of federal power,'” they added. “It is instead a significant encroachment on the lives – and health – of a vast number of employees.”
The decision comes as the US experiences another wave of Covid-19 infections, with the Omicron variant spurring record cases and hospitalisation rates.