The NHS plans to deliver an unprecedented 35 million flu jabs this winter amid fears the virus could overwhelm the health service while it battles Covid.
Older children and the over-50s will be among those to be offered a vaccine, raising the prospect that the flu and coronavirus jabs could be given at the same time.
Sajid Javid, the Health Secretary, said the UK must "learn to live with Covid-19", but that the free vaccine programme was being expanded to more people to "help keep them safe this winter".
The 35 million vaccines set to be offered is almost double the 19 million delivered in 2020, which was a record number.
Flu vaccines will be available from September for children aged two and three on August 31, primary and secondary school students, pregnant women and the over-50s.
Flu deaths are now ten times higher than Covid deaths
They will also be given to people in clinical risk groups, unpaid carers, close contacts of immunocompromised patients and front line health and care staff.
Two- and three-year-olds and schoolchildren will be offered the vaccine via a nasal spray.
The initiative comes amid concerns the UK has low levels of immunity from flu because of lockdowns and social distancing measures.
The Royal College of General Practitioners estimates that cases of flu were 95 per cent lower than normal last year, which could give rise to a bumper flu season this winter.
Seasonal flu usually kills around 7,000 people a year, but this year’s virus could infect many more people.
Officials are also concerned that patients who contract flu and coronavirus at the same time are twice as likely to die from the virus.
The Government hopes a widespread early vaccination system could reduce deaths and hospitalisations, preventing extra strain on the NHS while it deals with coronavirus patients.
Covid-19 deaths in 2020 were higher than every year of flu fatalities since 1918
A Department for Health spokesman said no final decision had been made on whether the flu jab would be given at the same time as a coronavirus vaccine for young people, or at the same time as a booster for older people who have already had two doses.
The Joint Council on Vaccination and Immunisation says third doses of Covid vaccines could also begin in September.
Urging people to take up the offer of a free flu jab, Mr Javid said: "Flu can be a serious illness and we want to build a wall of protection by immunising a record number of people.
"With the nation getting closer to normal life, we must learn to live with Covid-19 alongside other viruses and we’re offering the free flu jab to millions more people to help keep them safe this winter."
Dr Yvonne Doyle, Medical Director at Public Health England, added: "The flu vaccine is safe, effective and protects millions of people each year from what can be a devastating illness.
"Last winter, flu activity was extremely low, but this is no reason for complacency as it means less people have built up a defence against the virus. Combined with the likelihood that Covid-19 will still be circulating, this makes the coming flu season highly unpredictable."