The UK has experienced many waves of migration. Examples include:
1850s from Ireland, escaping famine
1940s onwards from India, Pakistan and Bangladesh, escaping civil war and seeking employment
1950s from West Indies, seeking employment
1972 Ugandan Asians, escaping political persecution
2004 onwards from eastern Europe, particularly Poland, seeking employment as a result of EU enlargement
Today, India is the most popular country from which migrants travel to the UK, with significant migration from Pakistan, Ireland and Poland.
In 2011, 13 per cent (7.5 million) of residents in England and Wales were born outside the UK.
Migration has both cultural and economic consequences for a country, which may be positive and negative.
Skills gaps are filled.
The economy benefits from hard-working people.
Public services benefit, eg workers in the NHS.
Government tax revenue increases.
Culture is enriched, eg world foods and festivals.
Immigrant groups boost the birth rate.
Pressure is put on services, housing and infrastructure.
Friction may develop between the host population and migrant groups, eg locals may feel they have missed out on job opportunities because of increased competition.
Migrants tend to be located together in large city areas.
Migrant groups may not assimilate into local communities.
Gender imbalance - usually more men migrate.
Many people also leave the UK every year. Australia, South Africa, Spain and the USA are popular destinations. People move for employment and educational opportunities. Some retire to a country such as Spain for a warmer and drier climate.