&gt; Then it seems that MPs might need to start deploying and using crypto in their everyday work<p>They should probably do that, especially for anything sensitive, whether or not GCHQ monitoring them is legal, both because the GCHQ might do illegal things and because the GCHQ might not be the only entity surveilling them.<p>OTOH, given Parliamentary sovereignty, its fairly trivial for Parliament to deal with the problem that GCHQ monitoring of their communications is <i>currently</i> legal, and this doesn&#x27;t seem to be something where just the <i>opposition</i> is unhappy (while the <i>government</i> has been positive on the ruling so far, at least some Conservative MPs have been quoted as concerned about the ruling in some of the published reports.)