Boris Johnson is under pressure to strengthen the UK’s borders after Scotland’s first minister Nicola Sturgeon announced plans for a Scottish supervised quarantine system for all people arriving from overseas.

Concerns are mounting about the London government’s approach to border security given more virulent strains of coronavirus.

England’s new light-touch hotel quarantine policy — which only applies to people returning from 30 “red list” countries with Covid-19 strains exhibiting highly transmissible mutations — may not be up and running until February 15, it has emerged.

The government does not know when it will be able to roll out the hotel quarantine restrictions, the aviation industry was told on Tuesday, with logistical details expected to be discussed further over the coming days.

February 15 would be three weeks after Priti Patel, the home secretary — an advocate of tougher border controls — first announced that people returning from the red list countries would be bussed to hotels where they would have to stay for 10 days.

Ms Sturgeon told the Scottish parliament on Tuesday that this was inadequate given the new variants of Covid-19.

She said these new viral strains could cross borders before being detected, while travellers might not come directly from countries on the managed quarantine list.

Ms Sturgeon said she still hoped that the UK government would introduce a “much more comprehensive” system than currently planned. If not, the Scottish government would push ahead with its separate system, although she did not give details.

On Tuesday health officials confirmed the discovery of 11 cases of the variant first detected in South Africa — in eight different areas of England — in people who had not travelled from that country. Health secretary Matt Hancock also said that 11 cases of a “mutation of concern” had been found in Bristol and 32 in Liverpool

Downing Street did not respond to Ms Sturgeon’s initiative. A government spokesperson said the detailed implementation of England’s hotel quarantine plan would be set out “in due course” given various operational challenges.

Labour has called for a total closure of the borders temporarily while the threat of the new overseas variants is assessed.

Nick Thomas-Symonds, shadow home secretary, called on Ms Patel to “reverse this reckless policy of leaving our borders unlocked and open to further risk”.

The Labour MP said the government’s own figures showed that under the current system only three in 100 people had been successfully contacted for quarantine compliance.

The idea of only applying hotel quarantine to people from the red list was “fatally flawed”, he argued, echoing Ms Sturgeon that new strains could come into the country indirectly from elsewhere.

But Jo Churchill, health minister, said Mr Thomas-Symonds sounded “a little like he wanted to shut down against the entire world” when a flexible programme would be more appropriate.

Scientists on the government advisory group Sage had warned weeks ago that only blanket hotel quarantine or full border closure could keep new variants out of the country, The Times newspaper reported.

Ms Sturgeon said Scotland had nearly eliminated community transmission of coronavirus last summer only to see the pandemic “reseeded” by arrivals from overseas. “We need to learn from past experience,” she said.

Enforced hotel quarantine for all arrivals is still limited to only a handful of countries, according to research by the Institute for Government, a think-tank.

A 14-day hotel quarantine has been applied to all arrivals in Australia since March 2020 with non-residents barred from entering the country apart from a few exceptions. New Zealand implemented a similar scheme in April last year.

Hong Kong introduced hotel quarantine for high-risk countries in July 2020 and has since extended it to 21 days — with a ban on people who have been in the UK or South Africa in the previous three weeks. In South Korea, non-resident arrivals must quarantine at a government-designated facility.