BORIS Johnson snubbed advice to impose a stricter border lockdown to stop mutant Covid strains - like the South African variant - entering Britain.
The PM reportedly overruled Sage scientists who urged him to force all travellers to quarantine in hotels on arrival in the UK.
🦠 Read our coronavirus live blog for the latest news & updates
Instead, he announced last week that only travellers from “high risk” countries will be forced to self isolate at the border.
Sage scientists had warned the PM that travel bans aimed only at certain countries would fail to block out new strains of the bug.
Only closing the borders totally or introducing mandatory quarantine for all travellers would “get close” to staving off the threat, The Times reported.
Home Secretary Priti Patel and the Health Secretary Matt Hancock both argued to close the borders.
But the PM overruled them and went ahead with the weaker controls instead.
Nick Thomas-Symonds, Labour’s Shadow Home Secretary, said: “These revelations are incredibly serious.
"Ministers have knowingly left the UK border open and potentially exposed people to new strains of the virus, in direct contradiction of their own Government scientists' advice.
"This puts the gains of the vaccine at risk, with disastrous consequences for people’s lives.
"The Home Secretary needs to come to Parliament urgently and reverse this reckless policy of leaving our Borders unlocked and open to further risk."
Yesterday, Mr Hancock confirmed there had been 105 cases of the South African strain confirmed in the UK - 11 of which were not linked to international travel.
Ministers have ordered mass door-to-door testing in the postcodes that the South African variant has been confirmed.
Residents in eight English postcodes from Surrey to Merseyside are being urged to get swabbed over the next fortnight.
Mobile units have been scrambled, while council officials will knock on doors offering kits to locals.
Authorities are anxious to suppress any spread amid fears vaccination will prove less effective against the variant.
It is more contagious than the original, but there is no evidence it is deadlier.
Speaking last night at the No 10 briefing, Matt Hancock pledged to “come down hard” on the strain.
The Health Secretary said it is “imperative” those in affected areas stay in and stick to the rules.
He warned: “This is a stark reminder the fight against this virus isn’t over yet.”
But scientists warn these cases could be the tip of the iceberg, with the real total up to 20 times higher. Only up to ten per cent of positive tests are “gene- sequenced” to look for variants.
Paul Hunter, the University of East Anglia’s professor of medicine, said: “The fact we are only doing surveillance on a minority of infections almost certainly means we have more cases in the UK.
"The concern is it is more contagious and also more resistant to vaccine.”
But Mr Hancock insisted the UK was working hard to stop it.
He said: “I strongly urge everyone in these areas to get tested, whether you have symptoms or not.
“A mutation in one part of the world is a threat to people everywhere. We need to come down on it hard, and we will.
"We’ve already made sure that all these cases are isolating, and that we’ve done enhanced contact tracing.
Most read in News
"We’re surging extra testing into the areas where this variant has been found and sequencing every single positive case. Working with local authorities, we’re going door to door to test people.”
READ MORE SUN STORIES
Transmission has been found at eight postcodes — in London, Surrey, Kent, Hertfordshire, the West Midlands and Merseyside.
All 350,000 locals will be offered a test over the next fortnight.