Toughened measures to prevent imported coronavirus variants gaining a foothold in the UK will be set out by ministers, with extra testing for all international arrivals.

People isolating at home will be told they must get a test two and eight days into their 10-day quarantine period, with Health Secretary Matt Hancock expected to give further details in the Commons.

The Department of Health and Social Care (DHSC) said the move was designed to provide a “further level of protection” enabling the authorities to track new cases more effectively.

It comes after it was confirmed last week that UK nationals returning from 33 “red list” countries would be required to quarantine in closely monitored Government-designated hotels, where they would have to take two tests – although no contracts have yet been signed with accommodation providers.

Environment Secretary George Eustice said officials remained confident the hotel quarantine plan will be up and running next week.

He told BBC Radio 4’s Today programme: “My understanding is that officials in the Department for Health are in discussion with a range of operators about procuring those hotels, and they are confident that they will get the capacity needed for the policy to start next week.”

The Financial Times reported that ministers were said to be close to signing up a series of hotels near Heathrow, and were optimistic of agreeing deals with others around Manchester, Gatwick, Birmingham and London City airports.

The extra testing burden – with the cost expected to fall on travellers – has added to concerns in the travel industry.

Paul Charles, from The PC Agency travel consultants and the Quash Quarantine campaign, told Today: “It’s quite clear we have entered a much tougher new phase where the Government wants to squeeze border entry and exit completely by adding these layers of complexity.”

If passengers had to pay for three tests – including one pre-departure – that will “obviously kill off travel, that will stop anybody really, even if they have to make an essential trip”, he added.

He suggested the furlough scheme would have to be extended to protect the travel industry.

Derek Jones, chief executive of luxury travel company Kuoni, welcomed the plan to test arriving travellers but called for it to coincide with an easing of mandatory self-isolation requirements.

He told the PA news agency: “A robust testing regime is the way to open up travel again but it has to replace or at least shorten quarantine.

“That’s the way to get travel moving again.”

The move comes as scientists sought to reassure the public that vaccines remained effective despite concerns about the Oxford/AstraZeneca jab’s performance against the South African variant.

South Africa has suspended use of that vaccine after a preliminary trial suggested it offered a reduced level of protection against infection and mild illness from the variant.

Professor Andrew Pollard, director of the Oxford Vaccine Group, told Today: “I think, in many ways, it’s exactly what we would have expected, because the virus is introducing mutations, as we’ve discussed before, to allow it to still transmit in populations where there’s some immunity.

“And we already knew in South Africa that the virus was able to cause mild infections in people who were infected earlier last year.

“So that is not surprising then that with vaccines, also with mild infection, it’s going to be possible to see that.”

But he added that vaccines “are still preventing severe disease and death”.

On Monday, England’s deputy chief medical officer Jonathan Van-Tam stressed the importance of getting a jab because the vaccines were effective against the strains circulating in the UK and the South African variant was unlikely to become dominant.

He said that it was possible people would need booster jabs as the vaccines were updated to deal with new variants, and that there were “a lot of steps behind the scenes” to ensure that could happen.

Meanwhile, early research by The Alan Turing Institute and Oxford University suggests that the NHS Covid-19 app has so far prevented 600,000 cases.