NHS workers told Correspondent Dan Rivers they were protesting as they wanted to be able to make their own "informed choice"
Hundreds protested outside the offices of the BBC in central London before marching to Trafalgar Square, while hundreds demonstrated in Liverpool and Manchester.
The government has made it a legal requirement for all NHS workers in England to have had two doses of a vaccine by April 1.
That means anyone who does not have their first jab by February 3 is expected to be told they will lose their job.
It is thought up to 70,000 frontline NHS workers remain unvaccinated.
NHS workers who face losing their jobs and protesters opposed to mandatory vaccinations told ITV News Correspondent Dan Rivers why they are against the policy
Exemptions will be given to those who do not have face to face contact with patients and those who are medically exempt.
A similar policy is in force for staff in registered care homes in England - they must have both jabs as a condition of deployment, unless they are exempt for valid medical reasons.
Despite the ruling, NHS workers and anti-vaxxers gathered to say it's unfair that they're being singled out, and they're being denied freedom of choice.
Protesters told ITV News they were willing to lose their jobs over the decision not to get vaccinated and felt it was not something that should be enforced.
"I will lose my job and I am happy for that because I believe in the principles of why we're all here... informed choice,"Jane Venables, a mental health bank nurse said.
"We're not going to be bullied or coerced into having something that we don't want,"midwife Kamera Marley said.
Another protester who was not an NHS worker said he did not feel it was right for health workers to lose their jobs after they had put themselves at risk and worked tirelessly throughout the pandemic.
The Manchester protest took place at Piccadilly Gardens and Liverpool's outside St Georges Hall.
Placards featured slogans including 'No NHS mandates', 'nurses against mandates' and 'my body my choice'.
In Manchester a break-away group entered the city's Arndale Centre handing out leaflets.
Dr Nikki Kanani, GP and deputy lead for the NHS Covid vaccination programme, said health care professionals “have a duty” to make sure they are protected.
Dr Kanani said: “Mandatory vaccination is a government policy but as healthcare professionals we all have a duty to make sure that we are protected, to make sure that our colleagues and our patients are protected.
“I know that our teams will be doing everything they can to continue to have vaccine confidence building conversations and offering that all important vaccination to staff who are yet to have their first, second or their booster dose.”
Asked if patients will suffer if the NHS loses staff due to mandatory vaccination plans, Dr Kanani said: “As we’ve seen through the pandemic, and of course those days before the pandemic that we don’t even think of very often, our NHS continues to deliver.
“What I want to say is to our patients who are listening – we will keep looking after you.
“That’s what we do in the NHS. Our general practice teams, our pharmacy teams, our healthcare services.
“We’re here for you, so don’t ever worry. The NHS is open. The NHS is there for you.”
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