Nov. 25: Net migration - the difference between people entering and leaving the UK - fell by 88 per cent last year due to Covid restrictions, official figures suggest.
Brexit was also a factor, according to the Office for National Statistics (ONS), but it stressed there was "no evidence of an exodus" from the UK.
The estimates show net migration in 2020 was 34,000, compared with 271,000 the previous year.
This was the lowest level of net migration for many years, the ONS said.
But it was "difficult to disentangle" the impact of the end of free movement from the EU from the effects of the pandemic, the statisticians said.
In March 2020, the public were told to stop all non-essential travel in a bid to prevent the spread of coronavirus, and air travel to and from the UK dropped by 95% in the early months of the pandemic.
The quarterly report found estimated that 268,000 people came to the UK during 2020, compared with 592,000 people in 2019.
At the same time, an estimated 234,000 left the country to live abroad - a fall on the 2019 number of 300,000.
Net migration in 2020 from the EU was negative, with 94,000 more EU nationals thought to have left the UK than to have arrived.
The ONS warned that its figures were based on "experimental research" and "subject to a high level of uncertainty".
The organisation was forced to suspend the International Passenger Survey, the traditional method of measuring migration through surveys at ports and airports. due to the pandemic.