Boris Johnson risks allowing a new Covid variant to “run rampant” through the country by further easing restrictions for EU and US travellers, Labour has claimed.

England is to allow people visiting from the US and the EU who are fully vaccinated against coronavirus to enter without the need to quarantine.

The new rules will be in place from 4am on Monday, with Transport Secretary Grant Shapps expressing hopes that the US will become more relaxed about allowing Britons to visit “in time”.

But following an encouraging few days in which Covid-19 case numbers in the UK have fallen from above 50,000 on July 17 to 27,734 by 9am on Wednesday, Labour sounded warnings over the impact of the travel changes.

Shadow transport secretary Jim McMahon said: “The Government’s track record on our borders has been one of recklessness and confusion.

“They are in danger of continuing this by setting out changes in policy, applying to England only, without the scientific data and criteria we need to make sure we don’t see another Johnson variant run rampant through the country and damage the effort of the British public.

“We want to see international travel opened up safely.

“Ministers need to be clear on what progress has been made on reaching reciprocal agreements for Brits travelling abroad – particularly regarding the NHS app being accepted as proof of Covid status.

“We also need a clear green and red list and the country-by-country data to back it up.”

The Scottish Government also announced the rule change will apply to fully vaccinated EU and US visitors to Scotland from Monday.

The Welsh Government said it “regrets” the move to remove the quarantine requirement in England, but added it would be “ineffective” to have different rules for Wales.

Ministers in Northern Ireland will consider their position on the charge at Thursday’s meeting of the powersharing executive.

Currently, only travellers who have received two doses of a vaccine in the UK are permitted to enter from an amber country – such as the US and most of the EU – without self-isolating for 10 days, except those returning from France.

Professor Christina Pagel, director of the clinical operational research unit at UCL, said she was worried about variants that are better at infecting people who are already vaccinated given that those who are fully vaccinated could still catch and pass on the virus.

Speaking to the Guardian, she said a “worrying new variant could emerge” in the US or Europe – or “a variant that emerges anywhere will spread everywhere” if travel were less inhibited between those places and the UK.

Hailing the policy change, Mr Shapps said: “Whether you are a family reuniting for the first time since the start of the pandemic or a business benefiting from increased trade, this is progress we can all enjoy.”

Asked whether he was confident the US and Europe would reciprocate in allowing fully vaccinated travellers from England without needing to quarantine, Mr Shapps said: “I’ve just spoken to my US counterpart today and in the US they still have an executive order which prevents travel from the UK, from Europe, from several other countries to the US.

“So we’re saying, ‘You can come here, you can come visit, you can come see friends, you can come as a tourist if you’ve been double vaccinated and follow the rules without quarantine’.

“We can’t change that on the other side but we do expect that in time they will release that executive order, which was actually signed by the previous president, and bans inward travel.”