The fateful decision in March – taken without “any scientific evidence” to justify it – is blamed for making the impact of coronavirus “far worse” than if restrictions had been imposed.
It meant many hundreds of Covid-infected passengers arrived every day – particularly from Spain, Italy and France – as the UK stood “almost unique” in rejecting border checks, the report says.
It was “a serious mistake that significantly increased both the pace and the scale of the epidemic in the UK, and meant that many more people caught Covid-19”, the Commons Home Affairs Committee concludes.
Strikingly, it says the Home Office refused to set out any scientific advice to explain the “grave error”, despite repeatedly promising to do so – a stance attacked as “completely unacceptable”.
“We were told that thousands more people with Covid-19 came back to the UK after that guidance was lifted,” she warned.
“So, in the middle of March, at a time when the number of people with Covid coming back into the UK was at its peak, they were going back to work or onto public transport or seeing family without any quarantine in place.”
Pointing out that other countries were imposing restrictions in March, Ms Cooper added: “That alone should have rung loud alarm bells for ministers and made them think again.”
In fact, almost 1.7 million passengers arrived in the UK in the first week of March – and, even in the week ending 22 March, almost 600,000 did so.
The committee’s inquiry heard that, in the crucial 10 days between scrapping isolation guidance and the lockdown, up to 10,000 infected people arrived.
Nearly a third came from Spain, with a further 43 per cent from Italy and France combined, the Covid-19 Genomics UK virus-sequencing consortium found. Only 0.08 per cent were from China.
Professor Neil Ferguson, the leading epidemiologist, told the committee: “Probably 90 per cent of cases imported into this country were missed by those border measures because we were not checking people.”
The all-party committee says it was “understandable” that flights were not simply stopped, “not least because of large numbers of British residents”.
But, on the rejection of restrictions on passengers’ movements, it adds: “The committee was unable to find any scientific evidence to justify this inexplicable decision.”
The report supports the introduction of travel corridors to safer countries and the sudden re-imposition of quarantine on tourists to Spain, while criticising the way that decision was made.
It calls for the Joint Biosecurity Centre’s “traffic light” assessment of the risks of travelling to different countries to be published, to give the public better information.
The MPs also pour scorn on the Home Office’s argument that 99.9 per cent of arrivals are obeying requirements to quarantine for two weeks, finally introduced in June.
They describe the claim, made by home secretary Priti Patel as “unreliable”, because it appeared to be based only a limited number of compliance checks made and three fines issued.
Accurate figures should be published fortnightly, to boost public confidence, the report says, arguing: “This will allow oversight of the entire process.”
The government should also investigate testing at ports and airports, already in place in countries including Iceland, Hong Kong and South Korea, the committee recommends.
A government spokesperson insisted that appropriate measures had been “introduced at the right time”, despite the failure to produce the scientific basis for the decisions.
“With passengers numbers significantly reduced, the scientific advice was clear that quarantine measures for those entering the country from abroad would be most effective when the UK has a lower level of infection,” the spokesperson said.
“Therefore, as the virus was brought under control here, border measures were introduced on 8 June to protect public health and help avoid a second peak that would overwhelm the NHS.”