The number of centenarians will increase eightfold in the same period, the ONS said.

This increase will mean that by 2037, one in 12 of the population will be aged 80 or over.

Responding to the figures, John Fox, managing director at Liberty SIPP, said from a pensions perspective, the UK is at “red alert”.

“The state pension system is already stretched and, looking at this report, it is set to come under infinitely more pressure in the years ahead,” he said.

“Unless the Government accepts the magnitude of the problem and looks into a way of making pension saving more accessible and part of everyday life, its actions are as irresponsible as not stocking up on vaccine for an impending epidemic.

“We need to put in place a body that will accept responsibility for the crisis and put together the coherent pension strategy that this country so badly needs.

“From a pensions perspective, we are at red alert. Unless people start actively saving for their retirements, many will be facing a retirement in poverty.”

The ONS also predicted that the average age of the population will increase from 39.7 years in 2012 to 40.6 years in mid-2022 and then 42.8 by mid-2037.

The UK population is expected to rise from 63.7 million in 2012 to 70 million by 2027 and to 73.3 million by 2037.

The surge will come from more births than deaths and net immigration into the country, the ONS said.