The UK government has always said there will be no compulsory Covid vaccination. It is only nervously dipping a toe in the waters of the vaccine passport issue, which could have implications for those who do not have one. But some employers appear prepared to dive straight in. “No jab, no job,” says Charlie Mullins, who runs Pimlico Plumbers. He wants to be able to tell his customers they have nothing to fear from a visit to fix their leaking pipes.

Care homes are understandably thinking hard about it too. They have vulnerable people to protect and the families on the outside will be more than anxious to know that an elderly mum or dad is being looked after by somebody who is fully vaccinated. Barchester Healthcare, the second-biggest care home provider in the UK, has spelled it out to its 17,000 staff that if they do not get vaccinated even though they are eligible, there will be no more shifts for them from the end of April, said the chief executive, Dr Pete Calveley.

It might seem a no-brainer, if we assume that the vaccines stop or at least reduce the risk of people giving Covid-19 to others. And of all the people you would expect to be fully vaccinated to protect the vulnerable from infections, care staff and NHS workers would surely be at the top of the list, even if plumbers are some way down.

But it is not so simple. Vaccination is not mandatory in the UK. Unlike France and Italy, we did not respond to the measles outbreak across Europe by requiring MMR (measles, mumps, rubella) vaccination for children as a condition of going to school (and UK take-up was ultimately better).

Vaccination has been recommended but not compelled even for healthcare workers. For years, significant numbers of NHS staff have declined vaccination against flu, even though they could pass it to someone at risk of dying from it. Over the 2019-20 winter, 73% of frontline healthcare workers had a flu jab, which was an improvement on the previous two years after a major effort to encourage better take-up, but still meant a quarter remained unvaccinated.

This winter, because of the pandemic, the flu vaccination figures are likely to be better, but we know that significant minorities of healthcare workers and care staff will not have either the flu vaccine nor the new Covid vaccines. Some among them will have medical reasons for that. Others have religious or philosophical beliefs – or are just uncertain.

As it is at the moment, the law protects their right to say no. The government has powers to deal with the current pandemic under the Public Health (Control of Disease) Act 1984, but that does not extend to enforcing medical treatment or vaccination on an individual who does not want it. Where the government cannot go (unless the law is changed), employers would have trouble going also.

Ethical bodies say there is a balance to be struck between the freedom and self-determination of an individual and the gains to be made in public health. It is not a straightforward equation. Complications include the fact that these vaccines have emergency authorisation – not full approval from regulatory bodies. Although they are looking amazingly safe and effective, data is still being gathered on how well they work. Compelling people to be vaccinated, whether directly or for fear of becoming unemployed, could mean they have not given genuine consent.

If employers want to avoid accusations of workplace discrimination, they may have to make exemptions for those who cannot be vaccinated, such as people whose suppressed immune system makes it impossible, and pregnant women who are not eligible. It is hard to imagine somebody who is sacked because they cannot be vaccinated for medical reasons not having a good case at an employment tribunal. Those with short-term contracts that have expired, however, may struggle to get work.

Calveley said YouGov polling showed the public agreed with Barchester. He added that legal advice had been taken which said that if the company had a sufficiently compelling reason to do it then “that actually overcomes the issue of being discriminatory”. Whether that goes for plumbers as well remains to be seen.