Net immigration to Britain peaked in 2023 at a higher level than previously thought, and a far greater number of Britons left the country in subsequent years, revised official data showed on Tuesday.

Britain’s Office for National Statistics said most of the revisions were due to using labour ministry data that better captured the presence of British nationals than earlier surveys of travellers at ports and airports.

The number of British nationals who moved to Britain between 2021 and 2024 was twice previous estimates and the number of Britons who emigrated was three times higher than before.

Revisions to the number of non-British, non-European Union nationals were small and the figures also showed that fewer EU nationals had left than previously estimated.

Political discourse in recent months has been dominated by high levels of non-EU immigration – both legal and illegal – with the Labour government setting out various policies to cut down arrivals.

Below are the key facts and figures from the revised data which covered the pandemic period:

New ONS estimates show overall net immigration to Britain peaked at 944,000 in year ending March 2023, higher than its previous estimated peak of 906,000 in the year to June 2023
The estimate for net immigration in the year to December 2024 was revised downward to 345,000 from 431,000, largely due to higher emigration by British nationals
Cumulative net immigration between 2021 and 2024 inclusive was around 97,000 lower than previously thought
Cumulative net emigration by British nationals from 2021-2024 was revised up to 412,000 from 44,000
Cumulative emigration figures for British nationals over the 2021-2024 period was revised up from 343,000 to 992,000
Cumulative immigration figures for British nationals from 2021-2024 was revised up from 317,000 to 623,000