[Lukasa]

I Am Not A Legal Scholar, but:

It is not clear to me that any of the constitutional documents in the UK enshrine a right to silence. The Right to Silence in the U.K. is generally built up on common law, not statue. Every essay I have ever found on this topic refers to the right to silence in the UK as predicated on common law, not on statute, let alone on a critical constitutional document that would require explicit repeal.

So yes, Parliament cannot implicitly repeal some documents. But I don't think that the Right to Silence is in any of those. Of course, citations to the contrary would be welcome!

EDIT: And in fact the law has been challenged, all the way to the ECHR. The challenge failed: https://www.theguardian.com/uk/2007/jun/29/transport.eu