Report by ITV News Home Editor Paul Brand
The arrival of the South African variant of coronavirus in the UK proves the government's border controls aren't working, Sir Keir Starmer has said when criticising Boris Johnson at Prime Minister's Questions.
Launching a stinging attack on the UK's border controls, the Labour leader said 21,000 people arrive in the UK every day, and new arrangements for people to quarantine at hotels upon arrival are "weeks away".
The government has promised to bring in mandatory hotel quarantining for arrivals from "red list" countries to ensure compliance with self-isolation requirements, but it has not yet been revealed when this policy will come into force.
Sir Keir asked why "schools are shut and our borders are open", as the prime minister refused to say when the new hotel arrangements would be enforced.
The Labour leader asked the prime minister why he did not follow advice from government scientists, who he said recommended "a complete pre-emptive closure of borders".
During PMQs, he told the Commons: "The biggest risk to the vaccine programme at the moment is the arrival of new variants such as the South African variant.
"On that issue, the Government's own scientists Sage said two weeks ago, and I quote, 'only a complete pre-emptive closure of borders or the mandatory quarantine of all visitors upon arrival can get close to fully preventing new cases or new variants'. So, pretty clear. "
The PM insisted the Scientific Advisory Group for Emergencies (Sage) did not recommend full border closures, adding it is "not practical to completely close of this country" because of how heavily the UK relies on imports.
"But we do have one of the toughest regimes in the world," he claimed, pointing out that all travellers to the UK are required by law to self-isolate upon arrival, and are banned from entering without proof they have had a negative result from a Covid-19 test taken within the past 72 hours.
Sir Keir said if border controls "were working the [South African] variant wouldn't be in the country".
The prime minister said if the government had listened to the Labour leader throughout the pandemic, "we would still be at the starting blocks because he wanted to stay in the EU's vaccine programme", which is lagging behind the UK's.
Professor Sir Mark Walport, former chief scientific adviser to the government, has said it is "almost impossible" to completely shut down the country and prevent highly transmissible new strains from other countries coming to the UK.
Home Secretary Priti Patel said "measures at the border have been clear and consistent from day one" of the pandemic, adding the new arrangements will laid out "in due course".
Asked why they had not yet been brought in, Ms Patel said there were "big" logistical and operational considerations involved.
Ahead of PMQs, the House of Commons observed a minute's silence in memory of Captain Sir Tom Moore and others who have lost their lives as a result of the Covid-19 pandemic.
Speaker Sir Lindsay Hoyle said of Sir Tom: "His dignity and determination in raising money to support the NHS charities caught the nation's mood at the most difficult time - he exemplified the best of our values."
The prime minister urged Britons to take part in a nationwide clip for Sir Tom at 6pm on Wednesday evening.
Also at PMQs, Sir Keir asked if the PM thinks new variants will only arrive in the UK from direct flights, as he attacked a travel ban that covers some countries but not others.
"We know from the first wave of the pandemic that only 0.1% of virus cases came from China where we had restrictions, whereas 62% came indirectly from France and Spain where there were no restrictions.
"Why does the Prime Minister think that the variants of the virus will behave differently and only arrive in the UK by direct flights?"
Mr Johnson replied: "It is not practical completely to close off this country as he seems to be suggesting. What is practical to do is have one of the toughest regimes in the world and to get on with vaccinating the people of this country."
Watch PMQs in full: