NHS England and Boris Johnson have made conflicting promises on the booster rollout, leaving plans to deal with the rapid spread of Omicron mired in chaos and confusion.
On Sunday evening, the prime minister said that "everyone eligible aged 18 and over in England will have the chance to get their booster before the new year."
However the NHS has promised a different target, pledging to offer all adults the chance to book a booster, rather than actually receive one.
Pressed on the conflicting advice on Monday morning, NHS England said: “The NHS vaccination programme will offer every adult the chance to book a COVID-19 booster vaccine by the end of the year."
People who book their booster before the end of the year may have to wait until January or February to actually receive their dose.
Asked whether the NHS and the PM were issuing conflicting messages, a spokesperson for No 10 said: “Everyone eligible aged over 18 over in England will have the chance to get their booster before the new year.
“Obviously there will be some individuals for whom — for example, if you contract COVID you’ll need to wait the 28 days requisite gap between your second dose and your booster — you might not be eligible. But those eligible will have the ability to get that boost.”
He added: “We believe that those aren’t in contradiction.”
Watch: PM announces new booster target in face of 'tidal wave'
Johnson made the statement to the nation following the announcement that the UK would be moving into COVID alert level 4 in response to the rapidly spreading Omicron variant.
The PM confirmed on Monday morning that at least one person has now died with Omicron in the UK.
It has since emerged that NHS staff were not told about the announcement in advance, leaving them scrambling to reallocate resources to the rollout.
Rachel Clarke, author and palliative care doctor, tweeted: "This morning please spare a thought for NHS staff who - at exactly the same time you did - found out last night from Boris Johnson they’d be delivering 1 million boosters a day from… today."
Health secretary Sajid Javid confirmed on Monday that some non-urgent procedures would be cancelled to free up clinicians' time to get jabs in arms.
In addition, armed forces personnel have been “made available” to support the health service administer booster vaccines, the Ministry of Defence has said.
Around 750 servicemen and women will help deliver jabs and co-ordinate the rollout in England and Scotland.
Some 600 personnel from across the Royal Navy, British Army and Royal Air Force have been made available to NHS England, delivering jabs in small teams across the country, and another 51 will help with planning, while more than 100 are assisting in Scotland, the MoD said.
The morning after the booster statement, the NHS website crashed as the public scrambled to book appointments.
Lateral flow shortages have also hit areas across the country, the day before double vaccinated COVID contacts are required to take daily lateral flow tests for seven days.
The government's website says there are no tests available, and there are widespread reports of lateral flow shortages in local pharmacies and chemists.
Speaking at a vaccination site visit on Monday, Johnson refused to rule out further restrictions should the situation regarding Omicron continue deteriorate.
“I think that what everybody needs to recognise is a couple of things – that Omicron is a very serious risk to public health, and that it’s spreading very fast, and I think there’s no room for complacency," he said.
Watch: PM confirms first UK Omicron death