Most licensed big airports won't allow this.
Even if there isn't a sole distributer of fuel contract they will just keep the H&S paper flowing in your direction. And in the very unlikely event you do succeed in ticking all the boxes the rules will be changed the next week.
I wouldn't be suprised if half of the fuel price increase in LVP is going straight to the airport.
Airports like monopolys and usually they try there very best to hedge out anything which doesn't give them a kick back. If there is nothing they can do about it they will try other means to limit the supplier.
I have always thought that the greggs baker at MAN was in this situation. 10 years ago everyone could get access to it. Now its in a back corner in arrivals and you have to know where it is to be able to get to it. Still always busy though as all operating crew know where it is, all the locals and airport workers do as well.