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1/ I am *still* seeing people claim that the PCR test has a 93% false positive rate. This has been debunked many times but let me have one more go...
2/ One source given for this claim is Dominic Raab saying "the false positive rate is very high, it's only 7% of tests that will be successful in identifying those that actually have the virus."
3/ He's talking about a Public Health England report that estimated only 7% of infected people coming into the country would be identified if we did testing at airports. Raab was wrong to mention false positives. It has nothing to do with that. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/909382/s0544-phe-double-testing-travellers-170620-sage-42.pdf
4/ As it happens, the PHE report was based on some stupid assumptions and was also wrong (the real figure is between 33% and 66%), but that's not important right now. https://velvetgloveironfist.blogspot.com/2020/10/the-bottomless-incompetence-of-public.html
5/ It's not about false positives. If anything it's about false negatives. And it certainly isn't about how many false positives the PCR produces. The 7% figure isn't about that at all. https://www.dailymail.co.uk/news/article-8867415/Airport-testing-catch-six-10-Covid-19-carriers-research-debunks-PHEs-claims-7.html
6/ So either you can believe that a politician who is not a scientist garbled his answer and misspoke or you can believe that Raab, in a moment of madness, let slip the hidden truth and undermined the government's entire conspiracy. Which is more likely?
7/ The other source is Boris Johnson, who said of testing at airports that "it only works in 7% of the cases". This, again, is based on the PHE report and testing at airports.
8/ Boris gives a better account of himself than Raab but even if you choose to willfully misinterpret what he's saying, he is talking about false negatives, not false positives.
9/ Finally, if 93% of positive tests are false, why were there only 500 a day in July when we were testing over 100,000 people, and why have they gone fifty-fold now now that we're only testing three times as many people?
10/ Why does the number of hospitalisations rise in line with the number of cases, and why does the number of deaths rise a few weeks later? 
11/ Even if every case identified in July was a false positive (which they obviously weren't), the false positive rate could not, as a matter of simple mathematics, be more than 0.5%.
