One in nine people in England were on the NHS waiting list for routine operations by the end of November and record numbers of patients had to wait more than 12 hours to be seen in A&E last month, official figures show.
Experts warned the 'shocking data' laid bare the wider impact of Omicron on the health service and highlighted that many patients were being 'let down' by the deepening crisis in the NHS.
Stats published by NHS England today showed a record 6million people were stuck on NHS waiting lists for elective care by the end of November, just as the ultra-transmissible variant began to take off.
More than 300,000 patients had waited over a year - often in pain - for ops such as hip and knee replacements or cataracts surgery. Of them, 18,500 had queued for two or more years.
Meanwhile, a total of 12,986 spent 12 or more hours in emergency departments before being treated in December — the most since records began in 2010 and up by a fifth from November.
At the same time, just 73 per cent of A&E patients were seen within the NHS' four-hour target, the lowest percentage ever. Separate data shows heart attack patients waited 53 minutes on average for an ambulance to respond to their 999 call.
Dr Tim Cooksley, president of the Society for Acute Medicine, said the latest data revealed an 'increasingly serious situation.'
He added: 'Here we are another month on with a further shocking set of data which highlights how so many patients are being let down as well as the strain our exhausted staff are under.
'Behind every data point is a person and we can't allow anyone to forget that. There are also amazing staff on the ground who continue to provide the best care they care in the most challenging of circumstances and seeing this data is demoralising for us all.
'We need to focus on why performance has continued to fall and struggle for years and build the solutions to drive improvement in both the short and long term. This is an increasingly serious situation.'
The NHS was already in crisis mode before Omicron took off, with staffing shortages, pandemic backlogs
