Over 1,000 more Romanian migrants are living in South Holland than a decade previous after transitional controls were lifted on citizens in 2014, new census figures show.
It comes as the new figures show the number of Romanians living in the UK has increased sixfold since 2011 – the largest increase from any other country.
But the Migration Observatory at the University of Oxford said that many EU citizens may have left the UK by March last year, following the end of the EU settlement scheme.
The 2021 census figures from the Office for National Statistics show 1,393 people born in Romania resided in South Holland at the end of March 2021 – up significantly from 58 in 2011, when the last census was conducted.
England and Wales have seen a surge in Romanian arrivals over the last decade.
There are now 539,000 Romanian residents across the countries, over six times more than the 80,000 in 2011, while every local area saw an increase.
Census deputy director Jon Wroth-Smith said that the latest figures reflect a decade of change, with the UK leaving the EU and the coronavirus pandemic impacting migration patterns.
As roughly one in six people in England and Wales are now born outside the UK, he added: “We can see Romanians have been a big driver in this change, while there have also been increases due to migration from India, Pakistan and Poland, as well as southern European countries such as Italy.
“We can also see that migration in the year prior to the census was lower in 2021 than it was in 2011.”
Romania joined the European Union in 2007, but citizens were not afforded full freedom of movement until 2014.
But Madeleine Sumption, director of the Migration Observatory, said that figures could be undercounted, and highlighted a potential change in the arrival of Romanian migrants since the census was taken in March 2021 due to tighter Brexit visa rules.
"Official estimates of the migrant population between the censuses appear to have been reasonably accurate overall, but they did undercount Romanians," Ms Sumption said.
"This may be because Romanian migrants were more likely to live in types of accommodation that aren’t surveyed, such as employer-provided housing on farms, or because Romanian citizens were less likely to respond to official surveys."
Brexit has also had an impact on Romanian migration, with Romanian citizens receiving only around 2,400 entry visas to live and work in the UK in the year to June, Ms Sumption added.
Half of these were short-term seasonal work visas that only last six months.
The number of residents across England and Wales born outside of the UK also increased, from 7.5 million (13.4%) in 2011 to 10 million (16.8%) last year.
In South Holland, 13,910 people (14.6%) were born in another country – up from 9.6% 10 years earlier.
Romanian citizens are now the fourth-most populous foreign-born group across England and Wales, behind India, Poland and Pakistan.