The NAO said that 214,000 people were quarantined in hotels for 11 nights between April and Dec 2021 after the policy took effect in Feb 2021. It has since been scrapped.

It revealed that 14,000 arrivals were able to claim exemptions, including government officials, key technicians, models and sports stars.

For those travellers required to self-isolate at home, the NAO said that there were potentially high levels of non-compliance, despite the Government spending £114 million on a contract with a private company for home visits.

The UK Health Security Agency (UKHSA) had used the company as part of its efforts to contact people meant to be self-isolating by phone call and text message.

However, the NAO said that between May 2021 and Feb 2022, the UKHSA estimated that on average, one third (33 per cent) of those required to isolate had not been doing so. The range of 26 to 42 per cent breaking the rules was above the 25 per cent non-compliance it had expected.

‘Rip-off’ travel testing market criticised

The NAO also confirmed that holidaymakers buying tests from private providers experienced “poor” service, from rip-off prices to late tests, resulting in people missing flights, and calling complaints lines where no one answered.

The NAO criticised the Government for its “limited oversight” of the testing market it created. By February this year, there were at least 369 firms selling testing kits at prices ranging from £15 to an extortionate £525 per person.

Even though firms listed on the Government’s website marketed themselves as “government approved”, the DHSC’s listing process gave “minimal assurance” they could provide the services.

Despite complaints about firms failing to deliver tests or results, the Government had still not formally responded to an inquiry recommending action to give the public quality assurance.

The NAO said that Whitehall departments spent at least £486 million on border restrictions, yet could not demonstrate the measures had achieved “value for money”.

It said that the Government should learn from its mistakes by setting up a system to assess and audit the risks to prevent further waste of public funds.

Gareth Davies, the chief executive of the NAO, said: “After two years of the pandemic and following the recent removal of travel restrictions, the Government has an opportunity to ensure that it develops a systematic approach to managing any future travel measures, applying the learning from Covid-19.”