Office for National Statistics says 916,000 Poles are living in UK, with Lithuanians the second largest eastern European group

Around 1.4 million eastern Europeans are living in Britain, including 916,000 Polish people, and 80% of them are in work, according to the most complete official picture so far.

A study on migration from the eight eastern European countries known as the EU8, conducted by the Office for National Statistics, shows Lithuanians are the second largest EU8 group in the UK, with 170,000 living in the country.

The ONS study confirms that the food product manufacturing industry is particularly dependent on migrants, with EU8 citizens making up 25% of the total workforce.

A third of all Czechs working in Britain are employed in banking and finance, and there are 83,200 eastern Europeans working in the health service, education or public administration.

The ONS also provides data on when EU-born residents of the UK first arrived in the country, showing that more than 1 million have been in England and Wales since the last century, including 623,000 who arrived before 1981.

Those figures include citizens of both eastern and western European countries. They confirm that 855,000 citizens of EU14 countries – which made up the EU before 2004 – came to live in England and Wales before 2000, compared with 474,000 who have arrived since 2000.

The majority (932,000) of the EU8-born people living in England and Wales arrived after 2000, with 182,000 arriving before 2000. And 100,000 came to England and Wales before 1981.

The figures raise the possibility that Britain’s offer on EU citizens’ rights after Brexit will lead to more than 1 million people who arrived in the UK at least 17 years ago being fingerprinted and required to apply for a “settled status” biometric residence document.

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The data does not take account of how many of these long-term residents have gained British citizenship. The ONS says the vast majority of Polish and other EU8 citizens keep their passports, with only 7,000 a year applying for British citizenship.

When it comes to securing reciprocal rights for British citizens living in eastern European EU countries, the ONS study shows the numbers involved are relatively small. Only 14,100 Britons live in the EU8 countries, including Poland, and 72% of them are working there. Only 6,000 people are claiming British state pensions in the EU8 countries.

Those eastern Europeans living in Britain are far more likely to be of working age than the resident British population, according to the study, with 74% of them in the 15-49 age bracket. Very few are aged over 65.