Thanks everyone

My boss has complained to the necessary people and they will be looking into alternatives. We've come to an agreement now though that those that can pay on cards and claim expenses will do so, those that can't pay on card can either get their manager to pay or ask me, but they need to have provisionally booked first and I will fax details accordingly to the hotel.
It means I'll probably only get 20 requests a week at the very most (can you hear me sigh through relief) which is not unreasonable.
Callie