ATC and Notam about upcoming flying display. Request to accept Hunter denied due to display. Jet Provost leaves and requests departure slot. Senior Air Traffic Controller is distracted by paperwork and authorises depart of Provost. Section of Vampires arriving in formation allocated same runway as departing provost. Vampires have to break off as runway controller spots Provost taxiing onto runway. ATC controllers watch on in disbelief. "Co-ordination is essential to flight safety".