The number of Romanians and Bulgarians living in Britain has risen by nearly 80% from 230,000 in 2014 to 413,000 last year, according to the Office for National Statistics.

The surge in numbers coming to live in Britain from the two countries that joined the European Union in 2007 reflects the removal of restrictions on their rights to work in the UK in 2014. The number of people coming may also reflect the outcome of the EU referendum last year.

The ONS says nearly 80% of Romanians and Bulgarians of working age in Britain are in jobs and only 11,500 are unemployed. The remainder work in the home, study or have taken early retirement.

While more than 413,000 Romanian and Bulgarian citizens are living in Britain only 6,200 British citizens live in Romania and Bulgaria.

The figures are included in the last of six ONS reports published on the dynamics of migration between Britain and the EU, focusing on the people most likely to be affected by Brexit. Romania and Bulgaria are officially known as the EU2 countries.

The government is due later in autumn to publish its immigration white paper, which is expected to set out a system of temporary residence permits for new EU migrants after Brexit without the right to settle in Britain. Those already in Britain on Brexit day with five years’ residence in the UK are to be offered “settled status” with the right to remain.

Rich Pereira, the deputy director for population statistics for the ONS, said: “The picture of migration between the UK and the EU2 countries clearly shows a somewhat lopsided balance of movement, with the UK evidently proving an attractive labour market for Romanian and Bulgarian citizens since those countries’ full accession to the EU.

“This presents an obvious area of concern for both those large numbers of citizens who have moved to the UK, and for the jobs they have been doing, as the UK continues its negotiations to leave the EU.”

The ONS analysis shows that 25% of those of working age from the two countries are self-employed. This compares with only 14% of the UK working population. The figures show that 23% of Romanians and Bulgarians of working age work in the distribution, hotel and restaurant industries, a further 23% work in construction. About 18% of Bulgarians work in banking and finance.

Their concentration in lower-skilled jobs is reflected in data on average wage levels. Citizens of the EU2 countries earn on average £8.33 an hour compared with the UK national average wage of £11.30 an hour.

Notable Britons of Romanian or Bulgarian descent include the politicians Michael Howard and John Bercow. The Bulgarian footballer Dimitar Berbatov has played for Tottenham Hotspur and Manchester United.

United Nations figures show there are 3.4 million Romanians living outside Romania and 1.2 million Bulgarians have emigrated. The largest Romanian migrant communities are in Italy (1.1 million), Spain (684,000), and Germany (657,000).