An estimated half a million Britons who do not consume animal products would not have to adhere to so-called "jabs for jobs" rules under employment laws, it has been claimed.
Big firms, including Netflix and Google, have already told many US staff they must be vaccinated before returning to work and Foreign secretary Dominic Raab said on Thursday that the rule was "smart policy".
The Covid vaccine does not contain animal products, but all medications currently go through animal testing.
Ethical veganism was ruled to be a protected characteristic at a tribunal last year.
It means any employers would risk legal action if they order staff to be vaccinated.
A spokesman for Lewis Silkin, a law firm, told the Telegraph: "Some ethical vegans may disagree with vaccinations on the basis that they will inevitably have been tested on animals.
"Ethical veganism has previously been found to amount to a belief, capable of being protected."
The protections mean that vegans and people in other categories, including some religious groups as well as those with certain disabilities or medical conditions, could mount a claim of constructive dismissal if forced to get the jab.