The UK population is set to pass the 70 million mark before the end of the next decade, according to official figures.
Demographers project that the number of inhabitants in the country will rise by 3.6 million, or 5.5%, over the next 10 years, increasing from an estimated 65.6 million last year to 69.2 million in mid-2026.
The Office for National Statistics said the population is projected to pass 70 million by mid-2029, reaching 72.9 million in 2041.
Over the next decade, 46% of UK population growth is projected to result from more births than deaths, with 54% attributed to net international migration.
Andrew Nash, of the ONS Population Projections Unit, said: "Over the period between mid-2016 and mid-2026 the population of the UK is projected to grow from 65.6 million to 69.2 million, reaching 70 million by mid-2029.
"England is projected to grow more quickly than the other UK nations.
"Over that period 54% of growth is projected to result directly from net international migration. The other 46% is because there will be more births than deaths.
"These projections suggest slower growth than the previous (2014-based) projections.
"This is because of lower assumptions about future levels of fertility and international migration, and an assumption of a slower rate of increase in life expectancy."