To prevent the roadmap out of lockdown restrictions being derailed, the Labour leader reiterated his call for a “comprehensive scheme” of hotel quarantine for all arrivals into the country.
As measures on socialising were relaxed on Monday — allowing six people to meet outdoors — Sir Keir said: “It’s good we have got to this stage of lifting some restrictions, we have got to be cautious about it.”
“I think the single biggest risk is, of course, what we are seeing happening in other countries where the numbers are still going up,” he told reporters.
“One of my primary concerns is that, under the government’s scheme, only 1 per cent of those coming from abroad is quarantining. That seems wrong.
“We should have a comprehensive scheme of quarantine because that, it seems to me, is the single biggest threat to the progress that we are making.”
Under current government rules, those travelling from “red list” countries to the UK must quarantine in a government-designated facility for 10 days on arrival while others must self-isolate at home and take multiple tests.
Labour has previously suggested “fatal flaws” exist in the programme and have called for the hotel quarantine system to applied for all arrivals into the country to prevent the fight against the disease being jeopardised.
Earlier, professor Sir Mark Walport, a former chief scientific adviser to the government, said data should be one of the deciding factors in whether people can travel abroad later this summer.
“Certainly at the moment many countries in Europe have got case numbers that are going up — there are 36,000 cases a day in France, 16,000 in Germany, 22,000 in Italy. The numbers speak for themselves.”
Next month, the Global Travel Taskforce is expected to publish a report into how overseas travel could resume, but ministers have said that holidays will not be permitted before 17 May at the earliest and those flouting the rule can face a £5,000 fine.
In recent weeks, scientists have raised concerns about the import of variants into the UK potentially undermining progress in bringing down case rates as the NHS continues to rollout Covid-19 vaccines across the population.
Health secretary Matt Hancock insisted on Monday that the door “is not shut” on foreign holidays this summer, but said the “biggest problem” was variants such as those first found in South Africa and Brazil.
“We’re not yet sure, but we’re doing the science in Porton Down, and watching very closely, and if that all goes well, then we haven’t got a problem and then we’ll be much more relaxed about international travel,” he said. We will know more over the next few weeks.”
Asked if there may be foreign holidays this summer, he said: “There may well be, I wouldn’t rule that out. The door is not shut, it’s just too early to say, but what we can say with confidence is that the unlocking at home is on track.”