I guess my concern is that failure to lease as A3 may result in a change of use request for something less desirable like a bookmakers. As I understand it a Neighbourhood Plan would not prevent this outright but would give us a stronger position in being part of the decision.

It seems odd to me that the agents/landlord can't see the benefit of gathering the obvious strong community feeling in their favour. Find out what the community wants and use that to market the property to suitable businesses. Win-win.