Prime Minister Boris Johnson said the move was a “significant milestone” in the nation’s vaccination programme.
More than five million people – from priority groups three and four – will be invited to have the jab from Monday.
It comes as 10 new mass vaccination hubs open across England.
The UK has also now closed its travel corridors until at least 15 February to protect against “as yet unidentified new strains” of Covid.
The expansion of the vaccination programme comes after the number of people to receive a first dose rose to 3.8 million across the UK – more than have tested positive (3.4 million) since the pandemic began.
However, people in the top two groups – care home residents, those aged 80 and over and front-line healthcare workers – should still be prioritised for vaccinations, the Department for Health and Social Care said.
People aged 70 and over and clinically extremely vulnerable individuals make up priority groups three and four.
Nadhim Zahawi, the minister responsible for the vaccine rollout, defended the decision to offer Covid jabs to the over-70s and clinically vulnerable.
He told BBC Radio 4’s Today programme on Monday that the over-80s “need not worry” if they hadn’t yet been invited for a jab.
He said as it was only areas where the majority of the over-80s had been vaccinated that people aged 70 and over were being invited for jabs. He added that by today, 50% of care home residents should have been vaccinated.
He said that although vaccine supply remained “lumpy”, he was “confident” of meeting the government’s target to vaccinate all 15 million people in the top four priority groups by mid-February.
Mr Zahawi earlier told BBC Breakfast that his “very strong instinct” would be for workers at greater risk of catching the virus, such as teachers and police officers, to be offered a Covid jab once all nine priority groups have been vaccinated.
After the top four priority groups, the next five groups include people aged 50 and over and those aged between 16 and 64 with underlying health conditions.
Mr Zahawi also said that he expected to see a “gradual” easing in coronavirus restrictions, potentially starting about two or three weeks after the most vulnerable groups had been vaccinated and had begun to receive protection from the jabs.
He said any lifting would be via England’s previous tiered system, but added there were “lots of caveats” as it was not yet known what impact the vaccine would have on transmission.
A further 298,087 people received their first dose of the vaccine on Saturday, and Health Secretary Matt Hancock said half of all those aged 80 and over had received at least one vaccine dose so far.
“We are now delivering the vaccine at a rate of 140 jabs a minute and I want to thank everyone involved in this national effort,” said Mr Johnson.
In a bid to meet the government’s mid-February target, 10 new vaccination hubs are opening in England from Monday, to go with the seven already in use.