LONDON- Net immigration to Britain fell by almost 90% last year to its lowest level since 1993 due to the impact of COVID-19 and Brexit, official figures showed on Thursday.

The Office for National Statistics released a first provisional estimate showing that 34,000 more people moved to Britain last year than emigrated, down from 271,000 in 2019.

"Immigration was much lower in 2020 than in previous years, likely caused by a combination of the coronavirus pandemic and Brexit," the ONS said.

Concern about unrestricted immigration from the European Union - which exceeded 200,000 on a net basis in 2015 - was a major feature of 2016's Brexit referendum. More recently, businesses have complained of labour shortages due to a lack of immigrants.

Britain left the European Union at the end of January 2020 - although EU citizens kept the right to move to Britain until the end of the year - but COVID caused foreign travel to grind to a halt from late March 2020.

The pandemic also severely hampered the ONS's ability to collect migration data as it stopped its traditional practice of surveying passengers at airports and ports.

The provisional data is based on experimental statistical modelling and is likely to be revised, with plausible estimates for 2020 ranging from net immigration of 125,000 to net emigration of 58,000, the ONS said.

Looking at non-British EU nationals alone, there was a net emigration of around 94,000, the ONS estimated.

Unlike most European countries, Britain does not have a system of identity cards or compulsory registration for residents that would make it easy to check migration flows.

"Although there is no evidence of an exodus from the UK in 2020, global travel restrictions meant the movement of people was limited, with all data sources suggesting migration fell to the lowest level seen for many years," ONS statistician Jay Lindop said.

(Reporting by David Milliken; editing by Guy Faulconbridge) ((david.milliken@reuters.com; +44 20 7542 5109; Reuters Messaging: david.milliken.thomsonreuters.com@reuters.net))