Researchers have called for an urgent investigation to find an explanation for more than 20,000 ‘additional deaths’ so far this year, amid severe pressure on the NHS.

Figures from the Office for National Statistics (ONS) show that in the first sixteen weeks of the year, there were 20,215 more deaths in England and Wales compared to the previous five years.

In March, academics raised concerns that Britain was facing a rise in mortality and argued that "health chiefs are failing to investigate a clear pattern of worsening health outcomes", in an editorial for the British Medical Journal (BMJ).

The piece centred on the finding that there were 10,000 ‘additional deaths’ in the first seven weeks of the year and concluded "that neither ‘flu, nor cold weather appeared to be the main cause."

Now the authors have now updated their findings to account for fresh statistics covering the first sixteen weeks of the year.

Their response, published on the BMJ website this week, argues that the latest statistics "sadly provide little reassurance of this being a ‘blip’ as some have suggested."

There were 198,943 deaths in the first sixteen weeks of 2018, compared to an average of 178,778 deaths in the same period over the previous five years. The rise represents an 11.3 per cent increase on the five year average.