So this one is another marathon read at 58 pages but it seems very thorough, with citations at the end exploring possible legal and human rights issue as framed by current law including ECHR.
bigbrotherwatch.org.uk/wp-content/uploads/2021/04/Access-Denied-Big-Brother-Watch.pdf
Trying to maintain due diligence, I could only find one claim that BigBrotherWatch had previously provided inaccurate information, with regards to costs to councils of CCTV, in 2011. Which could have just been a case of errors, and the organisation claimed that councils had given wrong information, so bit of a grey area. If anyone else knows of any reason they are a less than credible source, do hit me up.
However, the depth and range of the "vaccine / negative test" stuff, including looking at why and how it could be implemented seems very legit. The analysis of the companies involved in the tech research is also quite thorough.
Anyhoo, shall leave it for people to make their own minds up, and would love to hear the opinions of those who understand tech better than I 