Out with the old, in with the, err, old
Same suggestion over and over again, yet the mainstream media (I don't include El Reg in that title) don't discuss the key flaws in the concept suggested.
The biggest flaw is that you can grab an open source app, sideload it onto an Android phone and voila, you've got end to end encrypted comms which don't have the mandated back door in. Takes minutes to do.
So, fundamentally, this is not about catching criminals - they will use these tools if they don't want to get caught. It is still about mass surveillance of the population.
It'll last about as long as it takes for a Minister's private info to be hacked and released before it gets backtracked.