The current law in Britain allows for you to be sent to prison for refusing to give an encryption key to law enforcement. Surveillance in Britain has been present since means were available to do it. Not sure where the right balance is with this for us in Britain. Just to give perspective to the terrorism argument, it is real and we've got teenagers trying to get hold of bombmaking stuff. I know of four individual cases within a few miles of where I live over the past three or four years. And that's just one city, where a bomb not so long ago led to the whole city centre being rebuilt.
Difficult one really because the protections and safeguards should be in the use of powers to intercept and open, not in the ability to do it once judicial permission has been given. Need to see more details of what's intended and the checks and balances which are going to be present. Conservatives have in the recent past been a bit stupid with their thinking on the internet generally, so they don't start from a particularly good place.