Further update to this thread, i changed my mind and decided attempting to do this with checked baggage was too complicated. I finally got a useful response out of the London Algerian Consulate they told me you can transit without a visa if it's only in transit for a couple of hours.....then he went to check something and came back and said EXCEPT you can't do that at the moment as there is building work ongoing at the airport which prevents staying airside.
So i'm really none the wiser, sounds like i should be able to do it without a visa, unless his statement about the airport building works is accurate
