The UK’s population increased by 1% in a year, mainly due to net international migration, the Office for National Statistics (ONS) has said.
The total population of England, Scotland, Wales and Northern Ireland grew from an estimated 67.6 million in mid-2022 to 68.3 million in mid-2023.
The ONS said the extra 662,400 people amounted to an increase of 1%.
It is the largest annual numerical and percentage increase since comparable records began in 1971.
“Net international migration was the main contributor to population increase for all four countries of the UK in the year to mid-2023,” the ONS said.
Net international migration for the period is currently estimated to be 677,300.
However, officials cautioned that all estimates were likely to be revised within the next year as the ONS tries to improve its data.
The natural change in population, which is the difference between births and deaths, fell by 16,300. Previous projections from the ONS suggested a negative reading would not occur until the mid-2030s.
With the exception of 2020 during the COVID pandemic, the ONS said this was the first time there had been negative “natural change” in the population since 1976, although that year’s data was for the calendar year.
Read more from Sky News:
Water firms ordered to pay customers £157m
Hurricane Milton set to bring huge storm surge
Final moments of girl, 5, killed in Gaza
According to the estimates, published on Tuesday, England’s total population in mid-2023 was 57.7 million.
In Wales, there were 3.2 million people, while Scotland had 5.5 million and Northern Ireland had 1.9 million.
Latest migration figures show 1.16 million UK visas were granted for work, study or family reasons in the year ending June 2024.
Just over 75,000 people were granted permission to stay via schemes for refugees and for people from places such as Ukraine and the former British colony of Hong Kong.
During the same period, just over 38,700 people – a small proportion of the numbers coming to the UK – were detected arriving by “irregular routes”, such as small boat crossings.
It comes after the ONS projected in January that the UK population would grow to 70 million in two years.
By mid-2036, officials also said it could increase to 73.7 million, including net international migration of 6.1 million.
However, James Robards, from the ONS, said at the time that the projections were uncertain because they were based on assumptions about migration in previous years.