Surely it can be stopped by the courts though? They've helped force the UK back slightly on mass surveillance already [0]. I'm sure a challenge will be brought on the basis of freedom of expression (Article 10 ECHR) if any governments move to ban encryption. I mean it's an incredibly obvious impediment to free expression. I know personally if encryption goes I will be self-censoring a hell of a lot more (particularly when it comes to texting more extreme jokes for example).

Of course, with the UK leaving the EU and potentially tearing up the Human Rights Act it might not matter but as for the EU having power to stop this in EU member states I think the courts are the most likely solution.

[0] https://www.documentcloud.org/documents/3245181-C-203-15-amp...