Boris Johnson has urged the public to get a winter flu jab, saying it will help to protect the NHS.

The Prime Minister spoke as he promoted the expansion of the flu vaccination programme across England, in which up to 30 million people could receive the jab.

The Government is aiming to double its winter flu vaccination programme, with free jabs for those aged 50 and over and 11-year-olds.

This is on top of at-risk groups such as people with asthma, heart disease and diabetes, and anyone living with somebody on the Covid-19 shielded list.

The reason for doing this is to protect the NHS in the winter months because obviously we have still got Covid

Mr Johnson told Sky News: “We want everybody to get a flu jab in the run-up to this winter and that’s why we’re rolling out the biggest-ever programme of flu immunisation.

“And we’re aiming first of all for schoolchildren up to year seven, for pregnant women, for people over 65, for people who are shielded, but then we will be extending it to people who are 50 to 65.

“Now the reason for doing this is to protect the NHS in the winter months because obviously we have still got Covid, we have still got the threat of a second spike on Covid, and it’s vital therefore to keep that pressure off the NHS by everybody getting a flu jab and I really hope everybody will.”

At the moment, the free NHS flu programme is for people aged 65 and over, pregnant women, people with certain conditions such as kidney disease, asthma or heart disease, and carers or those in care homes.

Frontline health and social care workers are also eligible to receive the flu vaccine.

The flu jab is also free for children over six months with a long-term health condition, those aged two and three and those in primary school.

The programme will now be extended to include children who are aged 11 by the end of August this year – the first year of secondary school – and anyone aged 50 and over, who will be vaccinated later in the year.

Anyone living in a household with somebody on the NHS shielded patient list for Covid-19 will also be eligible for a free jab.

Experts hope GP surgeries will focus on high-risk groups before those aged over 50 in the fit and healthy range.

Not all GP surgeries will have enough fridge space to accept all the doses of the vaccine they will need but the aim is all those eligible will have had their vaccine by Christmas.

The Government hopes NHS and social care workers will also see it as their professional responsibility to get the flu jab but have not ruled out making it mandatory in future years.

Dr Dylan Watkins, a GP in Totnes, Devon, told BBC Radio 4’s Today programme his practice would struggle to administer the extra jabs.

“The concern is that for our practice we’ve got 15,000 patients and the addition of the cohort of patients in the 50 to 64-year-old age group is going to approximately double the number of flu vaccines we’re going to be asked to provide this year,” he said.

“(This is) at a time when we’re going to struggle to administer the vaccines effectively because of coronavirus limitations and we reckon with five clinical rooms running – each with administration staff with a nurse or doctor – that in a day we could probably administer 420 vaccines safely, according to the current guidelines.

“Add in an extra 2,000 patients for us that fall into this age category.

“Let’s estimate, maybe half of them might decide to have a flu vaccine this year … we’re looking at the full two days’ extra work while we’re also trying to play catch up on the clinical work we’ve been missing because of the coronavirus situation.”

He said it is a “huge guess” how many vaccines will be needed and who will take them up, adding 2,000 extra vaccines “sat in the fridge gone off” would cost £15,000.

Professor Martin Marshall, chairman of the Royal College of GPs, welcomed the move but added: “It is likely that Covid-19 will present challenges to delivering the flu programme.

“We will need to take measures to ensure all patients are safe when they come to get their vaccination, and we will need to ensure people, particularly in at risk groups, are confident in doing so.

“If a Covid-19 vaccination is available for use then this will also need to be factored in.”

The British Medical Association (BMA) said the expanded flu vaccination programme is “sensible given the current health climate” but said the Government will need to “ensure vaccination supplies reach practices quickly and in sufficient quantities”.

Health Secretary Matt Hancock said: “This will be the biggest flu vaccination programme in history and will help protect our NHS as we head into winter.

“If you are eligible for a free vaccine, whether it’s for the first time or because you usually receive one, then I would urge you to get it, not just to protect yourself, but to protect the NHS and your loved ones from flu.”

Jonathan Ashworth, Labour’s shadow health secretary, said: “Flu, alongside a second coronavirus wave, could be devastating.

“That is why Keir Starmer demanded that a comprehensive flu vaccination programme be put in place ahead of the winter, including free vaccinations for the over 50s.”

Researchers at the University of East Anglia (UEA) are investigating uptake of the flu vaccine among care home staff after surveys suggested it was as low as 20%.