The UK accreditation service (UKAS) is responsible for approving the 434 companies listed by the government as offering testing, but only 38 have so far been fully accredited - prompting complaints that holidaymakers are being exposed to "rip-offs".
On Tuesday (10 August), images of "overflowing and unsecure" PCR test drop boxes from private firm Randox led to an angry backlash from consumers.
Speaking to The Telegraph, chief executive of Airlines UK, Tim Alderslade, said the travel testing regime was becoming "more untenable by the day".
