Put under pressure in the Commons – after the Home Secretary’s astonishing revelation that she recommended closure last March – the prime minister twice ducked the question.
The fateful decision – taken without “any scientific evidence” to justify it, an investigation later found – is blamed for making the Covid-19 death toll “far worse” than if restrictions had been imposed.
It meant hundreds of Covid-infected passengers arrived every day – particularly from Spain, Italy and France – as the UK stood “almost unique” in rejecting border checks, a report by MPs said.
The controversy has been reignited after Ms Patel told Tory supporters: “On 'should we have closed our borders earlier', the answer is yes. I was an advocate of closing them last March.”
Instead, as coronavirus ripped through the UK, ministers abandoned asking people to quarantine for two weeks after arriving infection blackspots, such as Hubei province in China and Italy.
In the Commons, Keir Starmer demanded to know: “Why did he overrule his Home Secretary, who claims she said, last March, that we should shut down borders?”
But Mr Johnson refused to answer, instead branding the Labour leader “Captain Hindsight” for not having called for border closures himself, last March.
Speaking to reporters later, Mr Johnson’s official spokesman said that the government’s decisions had at all times been “based on the best scientific evidence and data available”, suggesting that Ms Patel’s support for closing borders was counter to the government’s assessment of that evidence.
But the spokesman said the PM continued to have “full confidence” in her as home secretary.
Outside the Commons, Nigel Farage also piled on the pressure, tweeting: “What a pity Boris Johnson didn’t listen to Priti Patel.”
Almost 1.7 million passengers arrived in the UK in the first week of March last year and, even in the week ending 22 March – days before the lockdown was finally imposed – almost 600,000 did so.
In the crucial ten days between scrapping isolation guidance and the lockdown, up to 10,000 infected people arrived, an investigation by the Commons Home Affairs Committee found.
Mr Johnson was also unable to answer questions posed about the blunder that saw the Home Office delete hundreds of thousands of criminal records
Sir Keir said: “It's 10 days since the Home Office mistakenly deleted hundreds of thousands of vital criminal records, including fingerprints, crime scene data and DNA records.
“So can the Prime Minister tell the House how many criminal investigations could have been damaged by this mistake?”
The Prime Minister replied: “We don't know how many cases might be frustrated as a result of what has happened.
“But I can tell him there are 213,000 offence records, 5,000 arrest records and 15,000 person records currently being investigated because they are the subject of this problem.”
Mr Johnson said the Home Office “believe that they will be able to rectify the results of this complex incident and they hope very much that they'll be able to restore the data in question”.