Express.co.uk readers can vote in our poll on whether the Prime Minister was too slow to order the coronavirus lockdown, which came into force on March 23. Home Office figures show between January 1 and the end of March 18.1 million people entered the UK.
Of those, 20,000 are estimated to have been infected with coronavirus.
They would have spread the virus to a further 50,000 people, based on the World Health Organisation’s assessment of an average transmission rate between 2 and 2.5 in early March.
Just 273 people arriving in Britain were quarantined.
People entering the country were only told to self-isolate if they had symptoms.
The Government has insisted they followed scientific advice that restrictions on arrivals to Britain would have had little impact on the spread of the virus.
But on Tuesday chief scientific adviser Sir Patrick Vallance told MPs on the Health and Social Care Committee that the UK imported cases from other countries.
He said: “One of the things that it looks like, very clearly, is that early in March the UK got many, many different imports of virus from many different places.
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It comes as the UK now has the highest death toll in Europe.
More than 32,000 have died but the rate is slowing and Mr Johnson is under pressure to lift the lockdown.
The Prime Minister, who has recovered from coronavirus, is expected to unveil his exit strategy later this week.
The prospect of the lockdown being eased comes as the latest figures show a total of 32,375 deaths involving coronavirus have been registered across the UK, compared to Italy’s toll of 29,315.