Anyone aged 18 or over can turn up at the sites, which include football stadiums, theatres, supermarket car parks and shopping centres, and get vaccinated. There is no need to book in advance.

The NHS will publicise the sites locally so people can opt to get jabbed on a trip to the shops or on the way to somewhere else.

“With more than 63 million jabs already delivered by the NHS in England, we’re now in a race to the finish line,” said Sir Simon Stevens, NHS chief executive. “It’s now easier than ever to get your life-saving jab, and the more of us who are vaccinated the safer and freer we all will be. So this weekend why not join millions of others and ‘GrabAJab’ to take advantage of this life-saving protection.”

A new online service enabling people to enter their postcode and find their nearest walk-in site is being set up and text messages will be sent to people living nearby who have not had their first dose.

Leading clinicians are also continuing to encourage everyone to come forward for their second dose and get maximum protection from the virus.

Jab buses will also be out on the road, and visits to housebound people are also planned, as the NHS gears up for a weekend of activity to drive uptake.

The move follows the watershed moment last Friday when every adult in the country became eligible for the jab.

A little more than a week since the system opened to everyone, over a third of people aged 18-24 already have been vaccinated.

People who attend a walk-in clinic for their first dose will have their vaccination record updated online and will then be able to book in their second dose appointment using the national booking system.

The NHS is vaccinating at the rate supplies becomes available in the run up to the 19 July target, as well as having offered second doses to all higher risk groups.

NHS England’s lead for the NHS vaccination programme, Dr Emily Lawson said: “Now is the time to get your vaccination with all adults now eligible. We all know they are lifesaving and getting jabbed helps protect us all from coronavirus, with thousands of brilliant staff ready to you get you vaccinated at the rate supply allows. If you haven’t yet got vaccinated for whatever reason, this is the weekend to get that sorted and join the tens of millions who have protected themselves and their loved ones from the virus. Please bring forward your second jab if it’s eight weeks or more since your first, when contacted to do so by the NHS, so that you get the maximum protection offered by the vaccines.”

Latest figures show the NHS in England has delivered over 62 million vaccinations just six months after making history when Margaret Keenan received the approved vaccine in Coventry.

Four in five adults have now received their first dose of the jab, with three in five already fully vaccinated after receiving two doses.

Second jabs are also available at the walk-ins, if it has been at least eight weeks since the first dose for people aged over 40, and 12 weeks for people aged under 40.

Getting the second dose is vital to getting longer lasting and maximum protection offered by the vaccines, with recent research also showing they are highly effective against the Delta/Indian strain of the virus.

“We are throwing open the doors of hundreds of vaccine centres across the country this weekend so anyone can just show up,” said Health and Social Care Secretary Matt Hancock. “I urge anyone who has yet to take up the offer to head to their nearest walk in centre this weekend and get the life saving jab.

“It’s becoming clearer all the time how effective our vaccines are in protecting against the Delta variant and with three in five people double vaccinated we’re well on our way to the whole country getting the fullest possible protection.

“So I’d urge everyone not yet fully vaccinated aged 18 and over to get your first and second doses as soon as possible to protect yourself and your loved ones.”

Vaccines Minister Nadhim Zahawi said: “Vaccines are our way out of this pandemic and, thanks to our NHS and the British public, they are already saving thousands of lives.

“No matter where you live, where you come from, your background or your beliefs – provided you are over 18, there is a vaccine available to you. I urge everyone eligible to get to their nearest walk in centre this weekend, get their jab and help us get back to normality.”

All adults can book at one of the 1,700 vaccination centre, pharmacy or general practice sites across the country that are available through the national booking service. Vaccination centres are also available in convenient locations such as mosques, museums and football stadiums. Details of the locations of the sites will be made available for communities across the country, so people can find the most convenient venue for them.

Text invitations appear as an alert from ‘NHSvaccine’ and include a web link to the NHS website to reserve an appointment.

People who cannot go online can call the service on 119 instead to book their jab.

People aged 39 and under who are eligible and pregnant women will be offered the Pfizer or Moderna vaccine in line with updated JCVI guidance.