The UK population is set to hit 72.5 million by mid-2032 – with the nearly five million almost entirely due to immigration.
Official projections show numbers are due to rise from 67.6million in mid-2022, even though deaths will completely offset births.
While births could increase slightly, deaths are also rising due to the aging ‘baby boom’ generation born after Second World War.
Across the period they should cancel each other out, with 6.8million of each, meaning there is no ‘natural’ change to the population anticipated.
Meanwhile, the level of net migration has been estimated to average 340,000 per year from mid-2028 onwards – significantly lower than current levels.
That suggests there will be net inflows of 4.9million over the 10 years to 2032.
The Office for National Statistics also projects an alarming rise in the older population, with a doubling of over-85s to 3.3million by 2047.
Numbers of state pension age are set to soar by 1.7million over the decade to 2032, to 13.7million people. More than one in 10 of the population could be over 75 at that point.
Official projections show numbers are due to rise from 67.6 million in mid-2022, even though deaths will completely offset births
The level of net migration has been estimated to average 340,000 per year from mid-2028 onwards – significantly lower than current levels
A population pyramid produced by the ONS showing a bulge in working age people
The overall population of the UK is projected to rise by 7.3 per cent between mid-2022 and mid-2032, compared with an increase of 6.1 per cent over the previous 10 years.
England’s population is projected to grow more quickly than other UK nations in the decade to mid-2032, increasing by 7.8 per cent, compared with 5.9 per cent for Wales, 4.4 per cent for Scotland and 2.1 per cent for Northern Ireland.
The ONS also provides a projection further into the future, covering the 25 years between mid-2022 and mid-2047, for which the total projected growth of the UK population is 8.9million, a jump of 13.2 per cent.
This is lower than the previous 25 years from 1997 to 2022, when the population is estimated to have risen by 9.3million, or 15.9 per cent.
ONS spokesman James Robards said: ‘The UK population is projected to grow by almost 5 million over the next decade.
‘The driver of this growth is migration, with natural change – the difference between births and deaths – projected to be around zero.
‘These projections are based on current and past trends, and aren’t forecasts about what may or may not happen in the future.
‘Our latest projections also highlight an increasingly ageing population, with the number of people aged over 85 projected to nearly double to 3.3million by 2047. This is in part because of the ageing of the baby boom generation, as well as general increases in life expectancy.’
