Immigration to add 6.1MILLION to the population by 2036
Official projections have suggested net inflows will add 6.1million to numbers over the next 12 years - nearly all the growth from the most recent estimate of 67million in mid-2021.
The rate of expansion has been upgraded, with the population now anticipated to hit 70million by mid-2026.
The Office for National Statistics figures come with the caveat that they are based on current trends rather than being predictions.
The projections also lay out the demographic challenges facing the country, with numbers aged over 85 expected to go up from 1.6million to 2.6million in 12 years' time.
The estimates assembled by an expert panel assume long-term net international migration of 315,000 a year from mid-2028 onwards.
Previously, long-term net migration was revealed to have reached a new record of 745,000 in 2022.
James Robards, ONS head of population and household projections, said: 'Expert views and the latest data covering the last 10 years has led us to develop a long-term net migration assumption of 315,000 each year from year ending mid-2028 onwards.
'It is important to recognise that there is uncertainty in the provisional international migration estimates.
'Future migration will be affected by policy changes as well as the impact of as yet unknown migrant behavioural patterns in the future.
'Put simply, if migration comes down, so will future projections.
'If net international migration were to be, say, 20 per cent higher than our long-term assumption, then it would be 379,000 per year.
'If it were to be 20 per cent lower than our assumption, then it would be 253,000 per year.
'That is why we call these projections and not forecasts. There is uncertainty and these differences would affect the total size of the population accordingly.'
The population of the UK is projected to grow from an estimated 67million in mid-2021 to 73.7million by mid-2036, an increase of around 6.6million or 9.9 per cent.
Over this period it is projected that 10.8million people will be born, 10.3million will die, 13.7million will move long term to the UK while 7.6million people will emigrate.
This means that of the projected 6.6million increase, 500,000 would come from a higher number of births than deaths, while 6.1million would result from net international migration.