A series of "critical errors" in the government's approach to travellers entering the UK made the coronavirus pandemic much worse, a cross-party group of MPs has said.
In a damning report, the Home Affairs select committee said a failure to implement proper quarantine measures in March led to "many more" people contracting Covid-19.
MPs were particularly critical of the government’s decision on 13 March to remove all self-isolation guidance for travellers arriving in the UK at a time when other comparable countries were strengthening their border measures.
That move came when hundreds of new Covid cases were arriving in the country every day – particularly from Spain, Italy and France, and including many Brits returning home.
The committee's report said it had been unable to find any scientific evidence to justify the "inexplicable decision" and that failing to put in place any special border measures was a "serious error".
"The government’s failure to have proper quarantine measures in place in March as the infection was spreading fast was a grave error and meant Covid spread faster and reached more people," said committee chair Yvette Cooper, a former shadow home secretary.
"The UK was almost unique in having no border checks or quarantine arrangements at that time. That alone should have rung loud alarm bells for ministers and made them think again."
The senior Labour MP added: "Many times ministers told us they were following the science, but we cannot find any science at all behind their completely inexplicable decision to lift all the self isolation guidance for travellers on 13 March a full ten days before lockdown, just at a time when other countries were introducing stronger border measures.
"We were told that thousands more people with Covid-19 came back to the UK after that guidance was lifted. 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."
Border measures ‘not taken seriously enough’
Evidence given to the committee suggests had Spain been added to the early list of countries from which travellers were required to quarantine on their return, along with other hotspots such as the Chinese province of Wuhan and Iran, the spread of infection could have been slowed.
Studies referenced by the government's chief scientific adviser, Sir Patrick Vallance, revealed more than 1,300 separate strains of the virus were imported largely from Spain, Italy and France.
Other evidence to the committee suggested up to 10,000 people with Covid-19 entered or returned to the country in March.
MPs were also critical of the communication around the decision to remove Spain from the list of "safe" countries at the end of July, following a spike in infections in the country.
It warned that the government "needs to be much more sensitive to the impact on families and businesses", calling for a 'traffic light assessment' of different countries so people can better judge the risk before travelling.
Cooper added: "We are concerned that border measures just weren’t taken seriously enough at the beginning of the crisis, either in the discussions among scientific advisers or in ministerial decision-making.
"It appears ministers took decisions without critical information they should have had, and it has been extremely difficult to work out who took key decisions and on what basis."
Cooper added it was "unhelpful" for ministers to have described travel corridors as "good news for holidaymakers” when they were announced earlier in the summer, prompting thousands to book international breaks.
"The mixed messages meant people booked holidays in Spain in good faith and now are put in a really difficult position," she added.
"In an unprecedented public health crisis, the government inevitably faces very difficult decisions. But they would be much more effective with greater transparency and trust.
"Publishing the science and evidence behind their decisions would mean they benefit both from greater scrutiny and debate to get those decisions right, and also from greater trust, understanding and support."
A Home Office spokesperson said the government had followed scientific advice.
"And 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," they added added.
"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."
Kate Forrester is a senior reporter at PoliticsHome, where a version of this story first appeared.