Pretty Obvious, Really, and Virtually Impossible to Avoid and Deny and Claim is not Necessary
A public clarification from the PM/Cabinet Office that such an immunity is inequitable and unlawful and bound to be abused for an evasion of common justice*, is needed to ensure that the public do not think that politicians think themselves above the law and greater than anyone else, and politicians do not get above themselves and think such to be so.
Certainly, in this modern day and internetworking age of cyber communications, are all smarter spooks comprehensively surveilling them to ensure they do what intelligence services required of the future rather than they, the elected political party hacks, arbitrarily and unilaterally servering what the past would wish of the present.
Such then leaves the question hanging, are serving intelligence services smarter spooky operations centres, or are they failing to provide intelligent novel dynamic lead?
* Methinks there will be no one with the right stuff and enough guts and a great pair of working balls to deliver that nugget to the people, and in not doing so, extraordinarily render to peoples everywhere the news that they be up to all sorts of unpleasant and unsupportable shenanigans. And would be wishing to continue to be doing more of the same.
What a load of plonkers be they then, and those in spooky positions that would not end such abuse.