Question to the Department of Health and Social Care:

To ask Her Majesty's Government, further to the Written Answer by Lord Bethell on 10 December (HL10848), what steps they have taken reliably to determine the operational false positive rate for polymerase chain reaction COVID-19 mass testing; and how they have made any such determination.

Polymerase chain reaction tests are very specific and the risk of false positives where the test is reacting to other viruses is extremely low. Independent confirmatory testing of positive samples indicates a test specificity that exceeds 99.3%, or a false positive rate of 1%, and additional guidance has been provided to laboratories to reduce the rate even further.