No matter how much she wants it, it will never happen.
Either her technical advisors are incompetent, or they've told her it's impossible and she's wasting everyone's time talking about it anyway.
It's almost as bad as the crap about breaking apps so messages can be read:
The manifesto makes reference to those increased powers, saying that the government will work even harder to ensure there is no "safe space for terrorists to be able to communicate online". That is apparently a reference in part to its work to encourage technology companies to build backdoors into their encrypted messaging services – which gives the government the ability to read terrorists' messages, but also weakens the security of everyone else's messages, technology companies have warned.