Whole thing is utter Tory cobblers.
Frankly, my main concern is this seguing from our being 'allowed' to physically intervene with unruly students, to our being expected to do so.
Dh teaches control & restraint (he works with adults with challenging needs): you have to know what you're doing - it's a disaster waiting to happen if physical restraint becomes routinely acceptable.
Teachers should NOT, on the whole, be physically preventing children from walking out of classrooms, or wading in to break up fights.
& as seeker says, there is no central policy prohibiting us from restraining kids if the (exceptional) circumstances actually warrant it.
Maybe I'm being paranoid, & it's just a silly Tory distraction, as wahwah says.