Updated 12 July, 2019

  • Four-fifths of population growth in the UK is the direct and indirect result of immigration – see our paper and the most recent ONS population projections.
  • Immigration added more than a million people to the UK (about equivalent to the population of Birmingham) every 3 years between 2001 and 2016 (more here).
  • The population hit a record 66.4 million in 2018. It rose by more than 4 million - equivalent to nearly half of London's population - over the past decade.
  • At current levels of immigration the UK population is projected to rise by a further 7.5 million over the next twenty years.
  • 80% of this increase, some six million additional people, would be due to immigration – equivalent to doubling the populations of Greater Manchester, Birmingham, Glasgow, Liverpool, Leicester and Sheffield.
  • The UK is already the most crowded large country in Europe.
  • 64% say the population is increasing too quickly; nearly three-quarters say the UK is crowded (YouGov polls, 2016-18)
  • Every serious study dismisses immigration as a way of addressing an ageing population. It would amount to a giant Ponzi scheme requiring continuous and ever-increasing flows of immigration, as previous arrivals themselves age.
  • The answer to an ageing population is for older people to work longer as many prefer to do. Employers need to adjust.
  • A sharp reduction in immigration is an urgent necessity in order to slow overcrowding, preserve our quality of life, save our beautiful green countryside and ease pressure on vital public services.

Recent Population Growth

1. The population now stands at 66.4 million (mid-2018) – see graph below. The latest ONS figures (for 2018) suggest the non-UK born population stands at 9.3 million (just over 14% of the total) of whom 3.6 million are from the EU and 5.7 million are from outside the EU.

Figure: UK population growth since 1971 – Office for National Statistics (ONS).

2. The population growth of a country is affected by the birth rate, death rate and net migration (the difference between immigration and emigration). Net migration adds to the population both directly from the arrival of people from overseas and indirectly from the children born to them in the UK.

3. Immigration is the main reason for the recent rapid rise in the UK population. In fact, four-fifths (82%) of population growth between 2001 and 2016 was due to the arrival of migrants and further children they have had in the UK. So immigration has added more than one million to our population every three years (read this paper for more). That is about the same number as the population of Birmingham – the UK’s second largest city.

4. In 2017, 28.4% of all births in England and Wales were to mothers born outside of the UK, the highest level on record. This percentage has increased every year (more than doubling in the process) since 1990, when the share was 11.6% (see graph below).

Figure 2: Percentage of live births to non-UK born mothers in England and Wales – ONS.

The UK is already overcrowded

5. With 274 people per square kilometer, the UK is the most crowded large country in the EU, with density being higher only in the Netherlands, Malta and Belgium.

6. Over 90% of international migrants to the UK come to England, which now has a population density of 430 people per square km. England is already nearly twice as crowded as Germany (which has 227 people per sq/km) and nearly four times as crowded as France (117 people per sq/km).

7. In the year to mid-2018, England’s population continued to grow at a faster rate (0.64%) than the other countries that make up the UK. Scotland, Wales and Northern Ireland grew at much slower rates (0.25%, 0.43% and 0.58% respectively) – see ONS bulletin.

Future population Growth

8. If net migration continues at recent levels the UK will become ever more crowded. Projections of future population growth have to make assumptions about net migration, birth rates and mortality but, in the UK, net migration has for some time been the largest driver of population growth.

9. The ONS produces projections on different assumptions about net migration. If net migration were reduced to zero (that is, the numbers of people entering and leaving the country were the same) the population would rise gradually to 67.3 million in twenty-five years before gradually declining from the middle of the century.

10. However, net migration is currently just over 250,000, far higher than the level assumed in the ONS’s main projection, and it has averaged nearly 300,000 annually over the past five years. At current levels of immigration, the population is projected to rise by a total 7.5 million over the next twenty years. Of this, six million (80%) would be due to immigration – equivalent to doubling the populations of Greater Manchester, Birmingham, Glasgow, Liverpool, Leicester and Sheffield.

11. Population growth would not stop there. It would continue to increase towards 80 million by mid-century and keep going upwards. These official government projections are illustrated below.

Figure 3. ONS Population Projections at different levels of migration.

12. The vast majority of population growth is projected to occur in England. Of the total increase by 2041 under the ONS’s main projection, 92% is due to take place in England. That would put further severe pressure on housing, transport services, schools, GP surgeries and hospitals.

13. Some claim that as the birth rate has decreased and life expectancy increases, the UK needs immigration in order to sustain the ratio of working age people to old age pensioners.

14. However, experts (e.g. Professor Christina Boswell of Edinburgh University; Professor Michael Murphy of LSE) have dismissed the idea that reliance on immigration is a panacea for dealing with issues surrounding ageing populations. As those arriving from overseas age themselves they would need to be replaced by an ever-increasing flow of immigrants to have any continuing effect on the age structure. A 2001 UN study estimated that only very substantial immigration levels would have any real impact in offsetting the ageing effect. Only a tiny minority (less than 10%) of the UK public would support increasing immigration in this way (according to virtually every poll conducted on the topic).

15. The ONS has noted that ‘higher levels of net migration slow population ageing but will not prevent it’. They add that the UK’s old age dependency ratio (the number of people of state pension age per 1,000 people of working age) is projected to increase regardless of future net migration levels.

16. Furthermore, the ONS has said that what they call the Active Dependency Ratio (the size of the economically inactive population against the size of the economically active population) is projected to increase less due to people who are around retirement ages working more. As the ONS concludes: “Projected changes in economic activity at older ages have a greater impact on future dependency rates than projected migration scenarios.” So a change in the retirement age would be a much more effective way of dealing with this issue.


17. Rapid population growth has a severe impact on the provision of public services such as school places. Similar strains will be placed on infrastructure, including the transport network. Roads will have to be widened and new ones built to deal with extra traffic while overcrowding on trains will increase. Adequate housing will have to be built to accommodate all the extra people, either by making our urban areas more overcrowded or by building on green field sites with the loss of countryside and productive farmland. Already, in recent years 90% of additional households in England have had a foreign-born head (ONS).

Government Policy

18. No UK government has had a population policy as such - that is to ensure that population growth is sustainable on any measure - but the present government came to power partially on the back of promises in their 2010, 2015 and 2017 election manifestos to reduce the level of net migration to the ‘tens of thousands’ (it is more than 250,000 currently). Achieving this would significantly slow the rate of population increase.