The increased demand for services is being driven by a far more contagious flu variant, a ‘drifted' influenza A(H3N2) strain, also now known as ‘subclade K'.

University Hospitals Birmingham NHS Foundation Trust, which operates the Queen Elizabeth Hospital in Selly Oak; Good Hope Hospital in Sutton Coldfield; Heartlands Hospital in Bordesley Green; and Solihull Hospital, declared a critical incident after treating 460 patients with flu on 8 December. 

The trust said: ‘This significant and sustained pressure is due in part to exceptional numbers of patients with flu requiring admission to hospital; this has now reached 269 inpatients and measures including mask-wearing in all clinical departments has been introduced.

‘Despite expanding capacity in our wards and in our emergency departments, our emergency departments (A&Es) remain overcrowded with extended waits to be seen.'

University Hospitals of North Midlands (UHNM), which operates Royal Stoke University Hospital and County Hospital in Stafford, has also reported high demand over the past week.

Katy Thorpe, UHNM chief operating officer, said: ‘We have taken the difficult decision to declare a critical incident. This helps us to take additional measures to maintain safe services for our patients and those in the community waiting for an ambulance.

‘Locally we are working with our NHS and local authority partners to ensure that people who need hospital and emergency care can get treatment quickly and to identify any additional support that allows us to discharge patients who do not require acute hospital care.'

The number of people in hospitals with flu in England is at a record level for this time of year. An average of 1,717 flu patients were in beds in England each day, including 69 in critical care, the most recent data showed. In London, hospitalisations are triple last year's figures.

Daniel Elkeles, chief executive of NHS Providers, told Times Radio: ‘I think we need to get back into the habit that if you are coughing and sneezing, but you're not unwell enough to not go to work, then you must wear a mask when you're in public spaces, including on public transport to stop the chances of you giving your virus to somebody else.

‘We were all very good about infection control during Covid. And we really, really need to get back to that now.'

He added: ‘We have really got to worry about the fact that this is a very nasty strain of flu.

‘It spreads very easily. It's warm and wet out there and people need to be sensible.'

Meanwhile, recent figures in Scotland show that flu cases have more than doubled in a week, with hospital admissions rising 70%.

NHS Ayrshire has made the 'difficult decision' to suspend routine visiting across all hospitals to protect patients, visitors, and staff. Only essential visits will be supported. The health board says it will review the situation daily.

Jennifer Wilson, nurse director at NHS Ayrshire, said: ‘Due to the increase in flu and other respiratory infections, and the high demand on hospital services, we must limit visiting to keep everyone safe. We know this is hard, especially at this time of year and we truly appreciate your understanding.'

In response, Scotland's health secretary, Neil Gray, said: ‘These are not decisions that are taken lightly. They're not unprecedented either. There's a very difficult balancing act that local teams will be needing to make around risk and the potential impact that can have on families and loved ones, which we're well aware of.

‘In terms of the vaccination programme already set out: there is more work to do, and I believe particularly amongst our staff groups, where I know our boards are doing what they can to provide drop-in clinics.'

Reaction

Conservative leader Kemi Badenoch told Sky News: ‘I'm still slightly traumatised by all the mask wearing that we had to do during Covid. Let's bring some common sense into this. I personally think that face coverings can be a barrier to social interaction, social cohesion and I do worry about a mask mandate.

‘I don't think the Government should be mandating anything. Let's have some common sense. I think people can make up their own minds. If you are really sick, it should be in bed. It should not be on public transport. I think that's more of a problem.'

A No 10 spokesman said: ‘There is long-standing guidance in place for people on a range of measures they can consider taking to help limit the spread of winter bugs if they have flu-like symptoms.

‘This is neither new nor an instruction but simply something people can consider when trying to limit the spread of winter respiratory illnesses. It's been a long-standing position. The best defence against flu is the vaccine, which is why we're ramping up our vaccination efforts this winter with almost 17 million flu jobs already delivered, which is 350,000 more than this time last year.'