Encryption is math, and not even hard math at that. You have as much chance of stopping evil people from using encryption as you have of stopping them from doing multiplication. Make every politician who opposes encryption feel like an idiot for thinking they can stop people from adding and multiplying.
From the article: "Tech companies should include mechanisms in the design of their encrypted products and services whereby governments, acting with appropriate legal authority, can obtain access to data in a readable and useable format" They would target companies, not math or protocols.
So drop the idea you can prevent encryption, learn to live with it. Drop the idea of giving your policemen ability to time travel and listen to anyones private conversation from the past while remaining invisible. It would be nice for you but physics (of internet) does not allow it.