The NHS England chief executive, Sir Jim Mackey, confirmed there is "no doubt" that this winter will challenge the health service more than ever, with hospitals already at full capacity and patients facing long waits.
England's top nurse has issued an urgent "flu jab SOS," encouraging people to get vaccinated to shield against severe illness.
"There is no doubt this winter will be one of the toughest the health service has ever faced."
— Sir Jim Mackey, NHS England Chief Executive
The vaccination appeal arrives just days before resident doctors in England plan to strike for five consecutive days, intensifying pressure on already stretched NHS services.
This winter, the UK faces extraordinary challenges from a severe flu season compounded by healthcare staff strikes, heightening risks for patients nationwide.