Justice and Security (Northern Ireland) Bill

I have two concerns about the ouster clause. First, merely allowing it to be in the Bill will lead almost inescapably to mission creep, whereby it is used more and more to return to the very thing that we are trying to get away from. Secondly, and even more importantly, what guarantee can the Minister give us that putting an ouster clause into Northern Ireland legislation will not be used as a precedent for introducing it in the rest of the UK, knowing as we do that the Government have tried to do exactly that in the past?