I think it is important to understand the base line when you look at a country like Norway, it is of course outside the European Union and it is free to do whatever it likes.
But the EU is an enormous trading partner sitting right on its border, it can't possibly not trade with it and in order to trade freely it has to accept freedom of movement, which is one of the founding principles of the EU.
So that is the bottom line reality. If you're talking about reform, stopping people coming here and claiming benefits for example, or using the NHS, there is a reasonable chance that might be negotiated or more measures might be negotiated.
But if you're talking about stopping people coming here and working I think that is much more difficult.
Yes, Mr Cameron is talking about new countries like Turkey maybe joining the EU and delaying that until they are richer, but I wouldn't bet on it and I wouldn't bet on getting our European partners to agree to that.