TENS of thousands of EU nationals could lose their right to be in the UK after Brexit without showing up in official data, according to

a new report.

It warned that unless the UK Government has a clear plan for measuring whether EU citizens living Britain have received “settled status”, the precise number who fall through the gap may never

be known.

The paper from the Migration Observatory at the University of Oxford said based on currently available statistics, it will not be easy to calculate exactly how many miss out unless the numbers are very large.

“This is because we do not have precise figures on how many EU citizens are living in the UK and plan to stay,” the report said. “It is possible that tens of thousands of EU citizens living in the UK could lose their legal status without this being clear from the data.”

Later this year, the government will launch an application system for EU nationals seeking to remain in the UK after Brexit. EU citizens who have been in the UK for five years by the end of 2020 will be able to apply for settled status, meaning they are free to go on living and working in the UK indefinitely. Those who have arrived by December 31, 2020, but do not have five years’ residence, can seek to stay until they have, at which point they can seek settled status. A Home Office spokesman said ministers had delivered on their commitment of securing EU citizens’ rights, adding: “The draft Withdrawal Agreement ... guarantees the rights of EU citizens and their family members living in the UK, and of UK nationals living in the EU.”