This is just a proposal at the moment.
Blunkett's tried these sort of things before yet he is usually thwarted by the Lords or the European Court of Human Rights.
Of course they can still choose to force it through using the Parliment Act, as they are with the foxhunting ban (only the third time in history it has been used), but they would have to renegotiate the Human Rights Act because as far as I'm aware these measures would be in direct contradiction.