As to the necessity of this consider this point.

At Liverpool the hotel next to the conference centre where everyone gathered in the evening and where there were loads of fringe meetings had no security at all. Nothing. Not even a badge check on the door.

We had more security for fringe events than that at Blackpool when we were nowhere near government.

The Liverpool hotel was on technically private land so there were no demonstrations etc immediately outside. However you could get access without showing a pass even on the day of Cleggs speech

Hywel