There is so much mis-information in this string of answers it is pitiful. The opinions expressed in this string are nothing more than that, and violate the moderator's rule, "But avoid . . . Making statements based on opinion; back them up with references or personal experience."
My advice, as a lawyer of more than forty years, is that nobody take the "opinions" of these non-lawyers seriously. I have not seen one single answer in this string that is accurate, but have found a lot of speculation, conjecture and misunderstanding of the law.
In fact, the UK does have laws that protect against self-incrimination. In other common law jurisdictions, they vary according to local law.
Privilege against self-incrimination, under common law and section 14(1) of the Civil Evidence Act 1968, a party may claim privilege against self-incrimination if compelled to disclose information that would tend to expose them to criminal proceedings for an offence or the recovery of a penalty. The risk of incrimination must be real and not remote or insubstantial.
The privilege against self-incrimination exempts a person from being compelled to answer a question when called as a witness, produce documents or provide information which might incriminate him in criminal proceedings and/or expose him to a penalty in England and Wales. It is based on common law privilege (Versailles Trade Finance Ltd (in administrative receivership) v Clough [2001] EWCA Civ 1509) and section 14(1) of the Civil Evidence Act 1968 (the CEA 1968).
In fact, in a civil case, where a defendant can show that there is a real risk of serious prejudice which may lead to injustice, the civil court has the jurisdiction to stay the civil proceedings until the related criminal proceedings have been concluded (Jefferson Limited v Bhetcha [1979] 1 WLR).
So, as you can see, there is a privilege against self-incrimination in the United Kingdom. The privilege can be traced to the 12th century and became more developed in the following centuries. The Latin term “nemo tenetur prodere seipsum” remains in use. It was applied on the Continent before the age of Codification. It was applied in English ecclesiastical courts also. It served as a guarantee that men and women would not be required to become the source of their own public prosecution and it was also a check on over-zealous officials.
This area of law is far too complex for non-lawyers to engage in and cannot be adequately discussed in this forum. If you want more information on this subject, as a beginning point for your research, I suggest: https://www.indymedia.org.uk/en/2005/09/323584.html. The Internet is a virtual source of information and there is no reason for anyone to speculate, as I have seen in this forum.
Disclaimer: The above is for the purpose of information only and is not intended as legal advice.