It may be legal for companies to insist that new staff be vaccinated as a condition of their employment, a minister has suggested.
However, Justice Secretary Robert Buckland said it was unlikely bosses would be able to make existing workers have vaccines under their contracts.
Downing Street has said it would be “discriminatory” to order people to be vaccinated to keep their job.
Several firms have said they will not take on new staff who refuse the jab.
In an interview with ITV on Wednesday, Mr Buckland said compelling new hires to be inoculated could, in theory, be possible if it was written into their contracts.
However, employers would probably need to take legal action if existing staff refused such an order, he said.
“I think that has to be the case because we’re dealing with existing terms of contracts of employment, thousands of existing contracts,” he said.
He added that the legality of “no jab, no job” would depend “very much on the terms of employment and the particular contract”.
“Generally speaking I’d be surprised if there were contracts of employment existing now that did make that approach lawful. I think frankly the issue would have to be tested.”
‘We’ve had the contracts drawn up’
London-based Pimlico Plumbers is one company that has said it will not hire new staff who have refused the vaccination on non-medical grounds.
Employment lawyers initially questioned the plan, but on Wednesday the company’s founder, Charlie Mullins, said he had been advised it was legal.
“More and more businesses are saying the same things,” he told Channel 4 News.
“We’ve already had the contracts drawn up, lawyers are very happy with them. They say it’s legal under health and safety laws and we have an obligation to protect our staff and our customers.”
Care home operator Barchester Healthcare has also said all new hires will be obliged to get the jab.
The Prime Minister’s official spokesman has said: “Taking a vaccine is not mandatory and it would be discriminatory to force somebody to take one.”